This PR is similar to #12403.
We previously conjectured that "all type class fields that are types
should be marked as reducible." The problem is that propositions are
types, but they are also used as data (with `Decidable`).
For example, we often see the proposition `x <= y` as a Boolean.
So, we refined the conjecture to:
"All type class fields that are types (and not propositions) should be marked as reducible."
This PR develops custom simprocs for dealing with `ite`/`dite`
expressions in `cbv` tactics, based on equivalent simprocs from
`Sym.simp`, with the difference that if the condition is not reduced to
`True`/`False`, we make use of the decidable instance and calculate to
what the condition reduces to.
Stacked on top of #12391.
This PR adds `IO.FS.Metadata.numLinks`, which contains the number of
hard links to a file.
This changes the implementation of `System.FilePath.metadata` and
`System.FilePath.symlinkMetadata` to use libuv. Otherwise, `st_nlink`
was not properly set on Windows. This also has the side benefit of
provided sub-second precision for file times on Windows (fulfilling an
old TODO). Also, while libuv supports `lstat` for Windows, enabling that
is left to a future PR.
This PR fixes a platform inconsistency in `IO.FS.removeFile` where it
could not delete read-only files on Windows.
The implementation now uses `uv_fs_unlink` instead of `std::remove`, as
libuv can delete read-only files. The PR also fixes a inconsistency in
`IO_test.lean` where it would generate files in the wrong directory when
run interactively.
---------
Co-authored-by: Markus Himmel <markus@himmel-villmar.de>
This PR fixes an issue in LCNF simp where it would attempt to act on
type incorrect `cases`
statements and look for a branch, otherwise panic. This issue did not
yet manifest in production as
various other invariants upheld by LCNF simp help mask it but will start
to become an issue with the
upcoming changes.
This is the proper fix for #6957.
This PR provides a `LawfulForwardPatternModel` instance for string
patterns, i.e., it proves correctness of the `dropPrefix?` and
`startsWith` functions for string patterns.
Note that this is "just" the correctness proof; there isn't a way to
actually use it yet. API lemmas will follow.
This PR adds identifying information about a module available to `lean`
(e.g., its name and package identifier) to the module's dependency
trace. This ensures modules with different identification have different
input hashes even if their source files and imports are identical.
This PR adds a few unification hints that we will need after
`backward.isDefEq.respectTransparency` is `true` by default.
See #12338
It was part of #12179.
This PR makes disabling the artifact cache (e.g., via
`LAKE_ARTIFACT_CACHE=false` or `enableArtifactCache = false`) now stop
Lake from fetching from the cache (whereas it previously only stopped
writing to it).
There are now 3 possible configuration of the local artifact cache for a
package:
* `true`: Artifacts will be fetched from the cache before building (if
available) and built artifacts will be cached.
* `false:`: Lake will neither fetch artifacts from the cache or store
them into it.
* **default** (no configuration set): Lake will fetch artifacts from the
cache but not store them into it. A key motivation for this is to, by
default, reuse artifacts downloaded into the cache from a remote
service.
This PR tags `List.reduceOption` with `@[expose]`. #12348 accidentally
moved the definition out of an `@[expose] section` which caused problems
in mathlib because `List.reduceOption` was expected to be exposed.
This PR extends shake with tracking of attribute names passed to
`simp`/`grind`.
On the way there, it also fixes `register_simp/grind_attr` uses outside
`public meta section` as well as go-to-definition on declaration-level
uses of the created attributes (tactic-level goto would be a separate
todo).
This PR moves the elaboration of structure/class Verso docstrings until
after the fact that it's a class is registered, so code samples in the
docstring can use it as a class. Redundant addition of structure and
constructor docstrings are also removed, because they're already handled
in MutualInductive.lean.
Closes#11651
This PR uses an `Array` instead of a `List` to store the clauses in
`Std.CNF`. This reduces the memory footprint and pressure on the
allocator, leading to noticeable performance changes with gigantic CNFs.
This PR treats the first character of the first line of a docstring as
being in the leftmost column, even if it physically is not. This allows
left-column items like headers to be used even after spaces. It also
detects the indentation of the entire docstring, using it as the
zero-point for indentation sensitive syntax such as headers.
Closes#12067.
This PR fixes poor error reporting from Verso docstrings. Before, if the
Verso parser didn't consume the whole docstring, then Lean would try to
parse the closing -/ and fail; this would lead to backtracking and an
assumption that the docstring must be non-Verso, with only the non-Verso
commands like #guard_msgs as possibilities. Now, the input is always
consumed.
Closes#12118.
This PR implements better support for unfolding class fields marked as
`reducible`. For example, we want to mark fields that are types such as
```lean
MonadControlT.stM : Type u -> Type u
```
The motivation is similar to our heuristic that type definitions should
be abbreviations.
Now, suppose we want to unfold `stM m (ExceptT ε m) α` using the
`.reducible` transparency setting, we want the result to be `stM m m
(MonadControl.stM m (ExceptT ε m) α)` instead of
`(instMonadControlTOfMonadControl m m (ExceptT ε m)).1 α`. The latter
would defeat the intent of marking the field as reducible, since the
instance `instMonadControlTOfMonadControl` is `[instance_reducible]` and
the resulting term would be stuck when using `.reducible` transparency
mode.
**Remark**: This feature introduces a few breakages in core and Mathlib.
So, it is disabled for now in this PR. To enable, we must use
`set_option backward.whnf.reducibleClassField true`
This PR adds two benchmarks (sieve of Eratosthenes, removing duplicates
from the list) and one test (a function with sublinear complexity
defined via well-founded recursion evaluated on large naturals with up
to `60` digits).
The tests have been suggested by @b-mehta.
This PR changes the semantics of `inline` annotations in the compiler.
The behavior of the original `@[inline]` attribute remains the same but
the function `inline` now comes with a restriction that it can only use
declarations that are local to the current module. This comes as a
preparation to pulling the compiler out into a separate process.
Closes: #12334
This PR changes the handling of over-applied cases expressions in
`ToLCNF` to avoid generating function declarations that are called
immediately. For example, `ToLCNF` previously produced this:
```lean-4
set_option trace.Compiler.init true
/--
trace: [Compiler.init] size: 4
def test x y : Bool :=
fun _y.1 _y.2 : Bool :=
cases x : Bool
| PUnit.unit =>
fun _f.3 a : Bool :=
return a;
let _x.4 := _f.3 _y.2;
return _x.4;
let _x.5 := _y.1 y;
return _x.5
-/
#guard_msgs in
def test (x : Unit) (y : Bool) : Bool :=
x.casesOn (fun a => a) y
```
which is now simplified to
```lean-4
set_option trace.Compiler.init true
/--
trace: [Compiler.init] size: 3
def test x y : Bool :=
cases x : Bool
| PUnit.unit =>
let a := y;
return a
-/
#guard_msgs in
def test (x : Unit) (y : Bool) : Bool :=
x.casesOn (fun a => a) y
```
This is especially relevant for #8309 because there `dite` is defined as
an over-applied `Bool.casesOn`.
This PR adds the option `doc.verso.module`. If set, it controls whether
module docstrings use Verso syntax. If not set, it defaults to the value
of the `doc.verso` option.
Closes#12070.
This PR fixes an issue on new NeoVim versions that would cause the
language server to display an error when using certain code actions.
(For some reason, NeoVim recently decided to diverge from VS Code in
terms of when it emits code action resolution requests, which means that
not setting the `data?` field won't preclude NeoVim from emitting a
request anymore, which in turn means that the server can't resolve the
code action.)
This PR implements preparatory work for #12179. It implements a new
feature in `isDefEq` to ensure it does not increase the transparency
level to `.default` when checking definitionally equality of implicit
arguments. This transparency level bump was introduced in Lean 3, but it
is not a performance issue and is affecting Mathlib. This PR adds the
new feature, but it is disabled by default.
This PR adds a default `Inhabited` instance to `Theorem` type.
The need to do so came up in #12296 , as `Theorem` is one of the entries
of the structure which is the key entry of `SimpleScopedEnvExtension`.
This PR fixes the PR release workflow which was failing due to the
deprecated `MATHLIB4_COMMENT_BOT` PAT being invalid.
**Error:** `jq: error (at <stdin>:4): Cannot index string with string
"name"` when fetching labels - the API returned an error response
instead of labels array because the PAT credentials were bad.
**Changes:**
- Generate a token from the `mathlib-lean-pr-testing` GitHub App (ID:
2785182) for posting comments to Lean PRs about mathlib compatibility
- Use `GITHUB_TOKEN` for read-only label fetching (no special identity
needed)
- Update the bot username check from `leanprover-community-bot` to
`mathlib-lean-pr-testing[bot]`
**Secrets added:** `MATHLIB_LEAN_PR_TESTING_APP_ID` and
`MATHLIB_LEAN_PR_TESTING_PRIVATE_KEY` have been added to the repository.
Fixes the CI failure at
https://github.com/leanprover/lean4/actions/runs/21705647318/job/62595966115🤖 Prepared with Claude Code
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
This PR adds `String.Slice.Subslice`, which is an unbundled version of
`String.Slice`.
This type is of interest because it is the correct type for string
searching and splitting operations to land in.
This PR just adds the type with minimal API. Additional API and
subsequent refactoring of the searching and splitting API is left for
future PRs.
This PR reverses the relationship between the `ForwardPattern` and
`ToForwardSearcher` classes.
Previously, it was possible to derive `ForwardPattern` (i.e.,
`dropPrefix?`) from `ToForwardSearcher` (i.e., get an iterator of
`SearchStep (s)`). Now, we give the default instance in the other
direction: it is now possible to derive `ToForwardSearcher` from
`ForwardPattern`. Since it is usually much easier to provide
`ForwardPattern` than `ToForwardSearcher`, this means more shared code,
which pays off double since we will give a correctness proof for the
default implementation in an upcoming PR.
This PR also adds some string lemmas.
This PR adds theorems that directly state that div and mod form an
injective pair: if `a / n = b / n` and `a % n = b % n` then `a = b`.
These complement existing div/mod lemmas and are useful for extension
arguments.
Upstreaming from
https://github.com/leanprover-community/mathlib4/pull/34201🤖 Prepared with Claude Code
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
This PR fixes the PR release workflow which is failing to create
`lean-pr-testing` branches due to the deprecated `MATHLIB4_BOT` PAT (see
https://github.com/leanprover/lean4/actions/runs/21698772126/job/62574742680).
The fix uses `actions/create-github-app-token@v2` to generate a token
from the `mathlib-nightly-testing` GitHub App (ID: 2784211) instead,
which has write access to both `leanprover-community/batteries` and
`leanprover-community/mathlib4-nightly-testing`.
Requires adding `MATHLIB_NIGHTLY_TESTING_APP_ID` and
`MATHLIB_NIGHTLY_TESTING_PRIVATE_KEY` secrets to leanprover/lean4
(done).
🤖 Prepared with Claude Code
This PR ensures `simp` does not "simplify" instances by default. The old
behavior can be retrieved by using `simp +instances`. This PR is similar
to #12195, but for `dsimp`.
The backward compatibility flag for `dsimp` also deactivates this new
feature.
```
set_option backward.dsimp.instances true
```
Applying `simp` (and `dsimp`) to instances creates non-standard
instances, and this creates all sorts of problems in Mathlib.
---------
Co-authored-by: Henrik Böving <hargonix@gmail.com>
Co-authored-by: Sebastian Graf <sgraf1337@gmail.com>
Co-authored-by: Kim Morrison <kim@tqft.net>
This PR leverages the fact that expressions are type correct in `grind`
and the conclusion of extensionality theorems is of the form `?a = ?b`.
This PR is relevant for #12179 because it enables us to use a weaker
`isDefEq` that does not bump the transparency level when processing
implicit arguments.
This adds a `maxSuggestions : Option Nat := none` field to both
`Simp.Config` and `Grind.Config`. When `suggestions` is enabled, this
field controls the maximum number of library suggestions to use. If
`none`, the default limit is used.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
This adds `set_option debug.byAsSorry true` and `decreasing_by sorry` to
various files to allow bootstrapping with Config structure changes. These
changes will be restored after the bootstrap dance is complete.
This PR adds and updates docstrings for syntax (and one for ranges).
The reference manual's section on syntax operators is gaining more
content, so the resulting docstrings were reviewed and the missing ones
added.
This PR adds an experimental `cbv` tactic that can be invoked from
`conv` mode. The tactic is not suitable for production use and an
appropriate warning is displayed.
This PR introduces the functions `(String|Slice).posGE` and
`(String|Slice).posGT` will full verification and deprecates
`Slice.findNextPos` in favor of `Slice.posGT`.
The KMP implementation is adapted to use these two new functions.
Various useful string and order lemmas are added along the way.
Also add a `simp` attribute to `Std.le_refl` and fix the resulting
fallout (yes, this would have been better as a separate PR).
This PR improves and simplifies the SymM-based mvcgen prototype by
creating `BackwardRule.apply`-ready auxiliary theorems for spec
theorems. These auxiliary theorems have types that have reducible
definitions unfolded and shared, just like the rest of the SymM world
assumes. Furthermore, in order to aid kernel checking times,
definitional reductions leave behind expected type hints. With #12290,
we get the following numbers:
```
goal_100: 100.671964 ms, kernel: 34.104676 ms
goal_200: 152.650808 ms, kernel: 70.653251 ms
goal_300: 222.973242 ms, kernel: 105.874266 ms
goal_400: 294.032333 ms, kernel: 150.025106 ms
goal_500: 366.748098 ms, kernel: 193.483843 ms
goal_600: 442.509542 ms, kernel: 236.845115 ms
goal_700: 517.527685 ms, kernel: 268.804230 ms
goal_800: 601.657910 ms, kernel: 310.765606 ms
goal_900: 681.020759 ms, kernel: 357.428032 ms
goal_1000: 762.212989 ms, kernel: 403.789517 ms
```
The baseline is `shallow_add_sub_cancel`:
```
goal_100: 62.721757 ms, kernel: 22.109237 ms
goal_200: 140.118652 ms, kernel: 45.219512 ms
goal_300: 241.077690 ms, kernel: 78.779379 ms
goal_400: 363.274462 ms, kernel: 128.951250 ms
goal_500: 517.350791 ms, kernel: 155.498217 ms
goal_600: 678.291416 ms, kernel: 212.325487 ms
goal_700: 881.479043 ms, kernel: 258.690695 ms
goal_800: 1092.357375 ms, kernel: 351.996079 ms
goal_900: 1247.759480 ms, kernel: 319.197608 ms
goal_1000: 1497.203628 ms, kernel: 364.532560 ms
```
The latter is with the main solving loop in interpreter mode, but the
kernel checking times are still representative.
Earlier experiments suggest that the precompiled baseline performs at
roughly 650ms for `goal_1000`, so the new mvcgen is getting close.
This PR moves the `PredTrans.apply` structure field into a separate
`def`. Doing so improves kernel reduction speed because the kernel is
less likely to unfold definitions compared to structure field
projections. This causes minor shifts in `simp` normal forms.
In preparation for adding the bench suite to the cmake-based test suite,
this PR moves test-related cmake code into the `tests` directory.
It also fixes a warning by removing an obsolete bit of the cmake code.
Bumps [actions/cache](https://github.com/actions/cache) from 4 to 5.
<details>
<summary>Release notes</summary>
<p><em>Sourced from <a
href="https://github.com/actions/cache/releases">actions/cache's
releases</a>.</em></p>
<blockquote>
<h2>v5.0.0</h2>
<blockquote>
<p>[!IMPORTANT]
<strong><code>actions/cache@v5</code> runs on the Node.js 24 runtime and
requires a minimum Actions Runner version of
<code>2.327.1</code>.</strong></p>
<p>If you are using self-hosted runners, ensure they are updated before
upgrading.</p>
</blockquote>
<hr />
<h2>What's Changed</h2>
<ul>
<li>Upgrade to use node24 by <a
href="https://github.com/salmanmkc"><code>@salmanmkc</code></a> in <a
href="https://redirect.github.com/actions/cache/pull/1630">actions/cache#1630</a></li>
<li>Prepare v5.0.0 release by <a
href="https://github.com/salmanmkc"><code>@salmanmkc</code></a> in <a
href="https://redirect.github.com/actions/cache/pull/1684">actions/cache#1684</a></li>
</ul>
<p><strong>Full Changelog</strong>: <a
href="https://github.com/actions/cache/compare/v4.3.0...v5.0.0">https://github.com/actions/cache/compare/v4.3.0...v5.0.0</a></p>
<h2>v4.3.0</h2>
<h2>What's Changed</h2>
<ul>
<li>Add note on runner versions by <a
href="https://github.com/GhadimiR"><code>@GhadimiR</code></a> in <a
href="https://redirect.github.com/actions/cache/pull/1642">actions/cache#1642</a></li>
<li>Prepare <code>v4.3.0</code> release by <a
href="https://github.com/Link"><code>@Link</code></a>- in <a
href="https://redirect.github.com/actions/cache/pull/1655">actions/cache#1655</a></li>
</ul>
<h2>New Contributors</h2>
<ul>
<li><a href="https://github.com/GhadimiR"><code>@GhadimiR</code></a>
made their first contribution in <a
href="https://redirect.github.com/actions/cache/pull/1642">actions/cache#1642</a></li>
</ul>
<p><strong>Full Changelog</strong>: <a
href="https://github.com/actions/cache/compare/v4...v4.3.0">https://github.com/actions/cache/compare/v4...v4.3.0</a></p>
<h2>v4.2.4</h2>
<h2>What's Changed</h2>
<ul>
<li>Update README.md by <a
href="https://github.com/nebuk89"><code>@nebuk89</code></a> in <a
href="https://redirect.github.com/actions/cache/pull/1620">actions/cache#1620</a></li>
<li>Upgrade <code>@actions/cache</code> to <code>4.0.5</code> and move
<code>@protobuf-ts/plugin</code> to dev depdencies by <a
href="https://github.com/Link"><code>@Link</code></a>- in <a
href="https://redirect.github.com/actions/cache/pull/1634">actions/cache#1634</a></li>
<li>Prepare release <code>4.2.4</code> by <a
href="https://github.com/Link"><code>@Link</code></a>- in <a
href="https://redirect.github.com/actions/cache/pull/1636">actions/cache#1636</a></li>
</ul>
<h2>New Contributors</h2>
<ul>
<li><a href="https://github.com/nebuk89"><code>@nebuk89</code></a> made
their first contribution in <a
href="https://redirect.github.com/actions/cache/pull/1620">actions/cache#1620</a></li>
</ul>
<p><strong>Full Changelog</strong>: <a
href="https://github.com/actions/cache/compare/v4...v4.2.4">https://github.com/actions/cache/compare/v4...v4.2.4</a></p>
<h2>v4.2.3</h2>
<h2>What's Changed</h2>
<ul>
<li>Update to use <code>@actions/cache</code> 4.0.3 package &
prepare for new release by <a
href="https://github.com/salmanmkc"><code>@salmanmkc</code></a> in <a
href="https://redirect.github.com/actions/cache/pull/1577">actions/cache#1577</a>
(SAS tokens for cache entries are now masked in debug logs)</li>
</ul>
<h2>New Contributors</h2>
<ul>
<li><a href="https://github.com/salmanmkc"><code>@salmanmkc</code></a>
made their first contribution in <a
href="https://redirect.github.com/actions/cache/pull/1577">actions/cache#1577</a></li>
</ul>
<p><strong>Full Changelog</strong>: <a
href="https://github.com/actions/cache/compare/v4.2.2...v4.2.3">https://github.com/actions/cache/compare/v4.2.2...v4.2.3</a></p>
<!-- raw HTML omitted -->
</blockquote>
<p>... (truncated)</p>
</details>
<details>
<summary>Changelog</summary>
<p><em>Sourced from <a
href="https://github.com/actions/cache/blob/main/RELEASES.md">actions/cache's
changelog</a>.</em></p>
<blockquote>
<h1>Releases</h1>
<h2>Changelog</h2>
<h3>5.0.1</h3>
<ul>
<li>Update <code>@azure/storage-blob</code> to <code>^12.29.1</code> via
<code>@actions/cache@5.0.1</code> <a
href="https://redirect.github.com/actions/cache/pull/1685">#1685</a></li>
</ul>
<h3>5.0.0</h3>
<blockquote>
<p>[!IMPORTANT]
<code>actions/cache@v5</code> runs on the Node.js 24 runtime and
requires a minimum Actions Runner version of <code>2.327.1</code>.
If you are using self-hosted runners, ensure they are updated before
upgrading.</p>
</blockquote>
<h3>4.3.0</h3>
<ul>
<li>Bump <code>@actions/cache</code> to <a
href="https://redirect.github.com/actions/toolkit/pull/2132">v4.1.0</a></li>
</ul>
<h3>4.2.4</h3>
<ul>
<li>Bump <code>@actions/cache</code> to v4.0.5</li>
</ul>
<h3>4.2.3</h3>
<ul>
<li>Bump <code>@actions/cache</code> to v4.0.3 (obfuscates SAS token in
debug logs for cache entries)</li>
</ul>
<h3>4.2.2</h3>
<ul>
<li>Bump <code>@actions/cache</code> to v4.0.2</li>
</ul>
<h3>4.2.1</h3>
<ul>
<li>Bump <code>@actions/cache</code> to v4.0.1</li>
</ul>
<h3>4.2.0</h3>
<p>TLDR; The cache backend service has been rewritten from the ground up
for improved performance and reliability. <a
href="https://github.com/actions/cache">actions/cache</a> now integrates
with the new cache service (v2) APIs.</p>
<p>The new service will gradually roll out as of <strong>February 1st,
2025</strong>. The legacy service will also be sunset on the same date.
Changes in these release are <strong>fully backward
compatible</strong>.</p>
<p><strong>We are deprecating some versions of this action</strong>. We
recommend upgrading to version <code>v4</code> or <code>v3</code> as
soon as possible before <strong>February 1st, 2025.</strong> (Upgrade
instructions below).</p>
<p>If you are using pinned SHAs, please use the SHAs of versions
<code>v4.2.0</code> or <code>v3.4.0</code></p>
<p>If you do not upgrade, all workflow runs using any of the deprecated
<a href="https://github.com/actions/cache">actions/cache</a> will
fail.</p>
<p>Upgrading to the recommended versions will not break your
workflows.</p>
<h3>4.1.2</h3>
<!-- raw HTML omitted -->
</blockquote>
<p>... (truncated)</p>
</details>
<details>
<summary>Commits</summary>
<ul>
<li><a
href="9255dc7a25"><code>9255dc7</code></a>
Merge pull request <a
href="https://redirect.github.com/actions/cache/issues/1686">#1686</a>
from actions/cache-v5.0.1-release</li>
<li><a
href="8ff5423e8b"><code>8ff5423</code></a>
chore: release v5.0.1</li>
<li><a
href="9233019a15"><code>9233019</code></a>
Merge pull request <a
href="https://redirect.github.com/actions/cache/issues/1685">#1685</a>
from salmanmkc/node24-storage-blob-fix</li>
<li><a
href="b975f2bb84"><code>b975f2b</code></a>
fix: add peer property to package-lock.json for dependencies</li>
<li><a
href="d0a0e18134"><code>d0a0e18</code></a>
fix: update license files for <code>@actions/cache</code>,
fast-xml-parser, and strnum</li>
<li><a
href="74de208dcf"><code>74de208</code></a>
fix: update <code>@actions/cache</code> to ^5.0.1 for Node.js 24
punycode fix</li>
<li><a
href="ac7f1152ea"><code>ac7f115</code></a>
peer</li>
<li><a
href="b0f846b50b"><code>b0f846b</code></a>
fix: update <code>@actions/cache</code> with storage-blob fix for
Node.js 24 punycode depr...</li>
<li><a
href="a783357455"><code>a783357</code></a>
Merge pull request <a
href="https://redirect.github.com/actions/cache/issues/1684">#1684</a>
from actions/prepare-cache-v5-release</li>
<li><a
href="3bb0d78750"><code>3bb0d78</code></a>
docs: highlight v5 runner requirement in releases</li>
<li>Additional commits viewable in <a
href="https://github.com/actions/cache/compare/v4...v5">compare
view</a></li>
</ul>
</details>
<br />
[](https://docs.github.com/en/github/managing-security-vulnerabilities/about-dependabot-security-updates#about-compatibility-scores)
Dependabot will resolve any conflicts with this PR as long as you don't
alter it yourself. You can also trigger a rebase manually by commenting
`@dependabot rebase`.
[//]: # (dependabot-automerge-start)
[//]: # (dependabot-automerge-end)
---
<details>
<summary>Dependabot commands and options</summary>
<br />
You can trigger Dependabot actions by commenting on this PR:
- `@dependabot rebase` will rebase this PR
- `@dependabot recreate` will recreate this PR, overwriting any edits
that have been made to it
- `@dependabot merge` will merge this PR after your CI passes on it
- `@dependabot squash and merge` will squash and merge this PR after
your CI passes on it
- `@dependabot cancel merge` will cancel a previously requested merge
and block automerging
- `@dependabot reopen` will reopen this PR if it is closed
- `@dependabot close` will close this PR and stop Dependabot recreating
it. You can achieve the same result by closing it manually
- `@dependabot show <dependency name> ignore conditions` will show all
of the ignore conditions of the specified dependency
- `@dependabot ignore this major version` will close this PR and stop
Dependabot creating any more for this major version (unless you reopen
the PR or upgrade to it yourself)
- `@dependabot ignore this minor version` will close this PR and stop
Dependabot creating any more for this minor version (unless you reopen
the PR or upgrade to it yourself)
- `@dependabot ignore this dependency` will close this PR and stop
Dependabot creating any more for this dependency (unless you reopen the
PR or upgrade to it yourself)
</details>
Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Bumps
[actions/download-artifact](https://github.com/actions/download-artifact)
from 6 to 7.
<details>
<summary>Release notes</summary>
<p><em>Sourced from <a
href="https://github.com/actions/download-artifact/releases">actions/download-artifact's
releases</a>.</em></p>
<blockquote>
<h2>v7.0.0</h2>
<h2>v7 - What's new</h2>
<blockquote>
<p>[!IMPORTANT]
actions/download-artifact@v7 now runs on Node.js 24 (<code>runs.using:
node24</code>) and requires a minimum Actions Runner version of 2.327.1.
If you are using self-hosted runners, ensure they are updated before
upgrading.</p>
</blockquote>
<h3>Node.js 24</h3>
<p>This release updates the runtime to Node.js 24. v6 had preliminary
support for Node 24, however this action was by default still running on
Node.js 20. Now this action by default will run on Node.js 24.</p>
<h2>What's Changed</h2>
<ul>
<li>Update GHES guidance to include reference to Node 20 version by <a
href="https://github.com/patrikpolyak"><code>@patrikpolyak</code></a>
in <a
href="https://redirect.github.com/actions/download-artifact/pull/440">actions/download-artifact#440</a></li>
<li>Download Artifact Node24 support by <a
href="https://github.com/salmanmkc"><code>@salmanmkc</code></a> in <a
href="https://redirect.github.com/actions/download-artifact/pull/415">actions/download-artifact#415</a></li>
<li>fix: update <code>@actions/artifact</code> to fix Node.js 24
punycode deprecation by <a
href="https://github.com/salmanmkc"><code>@salmanmkc</code></a> in <a
href="https://redirect.github.com/actions/download-artifact/pull/451">actions/download-artifact#451</a></li>
<li>prepare release v7.0.0 for Node.js 24 support by <a
href="https://github.com/salmanmkc"><code>@salmanmkc</code></a> in <a
href="https://redirect.github.com/actions/download-artifact/pull/452">actions/download-artifact#452</a></li>
</ul>
<h2>New Contributors</h2>
<ul>
<li><a
href="https://github.com/patrikpolyak"><code>@patrikpolyak</code></a>
made their first contribution in <a
href="https://redirect.github.com/actions/download-artifact/pull/440">actions/download-artifact#440</a></li>
<li><a href="https://github.com/salmanmkc"><code>@salmanmkc</code></a>
made their first contribution in <a
href="https://redirect.github.com/actions/download-artifact/pull/415">actions/download-artifact#415</a></li>
</ul>
<p><strong>Full Changelog</strong>: <a
href="https://github.com/actions/download-artifact/compare/v6.0.0...v7.0.0">https://github.com/actions/download-artifact/compare/v6.0.0...v7.0.0</a></p>
</blockquote>
</details>
<details>
<summary>Commits</summary>
<ul>
<li><a
href="37930b1c2a"><code>37930b1</code></a>
Merge pull request <a
href="https://redirect.github.com/actions/download-artifact/issues/452">#452</a>
from actions/download-artifact-v7-release</li>
<li><a
href="72582b9e0a"><code>72582b9</code></a>
doc: update readme</li>
<li><a
href="0d2ec9d4cb"><code>0d2ec9d</code></a>
chore: release v7.0.0 for Node.js 24 support</li>
<li><a
href="fd7ae8fda6"><code>fd7ae8f</code></a>
Merge pull request <a
href="https://redirect.github.com/actions/download-artifact/issues/451">#451</a>
from actions/fix-storage-blob</li>
<li><a
href="d484700543"><code>d484700</code></a>
chore: restore minimatch.dep.yml license file</li>
<li><a
href="03a808050e"><code>03a8080</code></a>
chore: remove obsolete dependency license files</li>
<li><a
href="56fe6d904b"><code>56fe6d9</code></a>
chore: update <code>@actions/artifact</code> license file to 5.0.1</li>
<li><a
href="8e3ebc4ab4"><code>8e3ebc4</code></a>
chore: update package-lock.json with <code>@actions/artifact</code><a
href="https://github.com/5"><code>@5</code></a>.0.1</li>
<li><a
href="1e3c4b4d49"><code>1e3c4b4</code></a>
fix: update <code>@actions/artifact</code> to ^5.0.0 for Node.js 24
punycode fix</li>
<li><a
href="458627d354"><code>458627d</code></a>
chore: use local <code>@actions/artifact</code> package for Node.js 24
testing</li>
<li>Additional commits viewable in <a
href="https://github.com/actions/download-artifact/compare/v6...v7">compare
view</a></li>
</ul>
</details>
<br />
[](https://docs.github.com/en/github/managing-security-vulnerabilities/about-dependabot-security-updates#about-compatibility-scores)
Dependabot will resolve any conflicts with this PR as long as you don't
alter it yourself. You can also trigger a rebase manually by commenting
`@dependabot rebase`.
[//]: # (dependabot-automerge-start)
[//]: # (dependabot-automerge-end)
---
<details>
<summary>Dependabot commands and options</summary>
<br />
You can trigger Dependabot actions by commenting on this PR:
- `@dependabot rebase` will rebase this PR
- `@dependabot recreate` will recreate this PR, overwriting any edits
that have been made to it
- `@dependabot merge` will merge this PR after your CI passes on it
- `@dependabot squash and merge` will squash and merge this PR after
your CI passes on it
- `@dependabot cancel merge` will cancel a previously requested merge
and block automerging
- `@dependabot reopen` will reopen this PR if it is closed
- `@dependabot close` will close this PR and stop Dependabot recreating
it. You can achieve the same result by closing it manually
- `@dependabot show <dependency name> ignore conditions` will show all
of the ignore conditions of the specified dependency
- `@dependabot ignore this major version` will close this PR and stop
Dependabot creating any more for this major version (unless you reopen
the PR or upgrade to it yourself)
- `@dependabot ignore this minor version` will close this PR and stop
Dependabot creating any more for this minor version (unless you reopen
the PR or upgrade to it yourself)
- `@dependabot ignore this dependency` will close this PR and stop
Dependabot creating any more for this dependency (unless you reopen the
PR or upgrade to it yourself)
</details>
Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
This PR shifts the conversion from LCNF mono to lambda pure into the
LCNF impure phase. This is preparatory work for the upcoming refactor of
IR into LCNF impure.
The LCNF impure phase differs from the other LCNF phases in two crucial
ways:
1. I decided to have `Decl.type` be the result type as opposed to an
arrows from the parameter types to the result type. This is done because
impure does not have a notion of arrows anymore so keeping them around
for this one particular purpose would be slightly odd.
2. In order to avoid cluttering up the olean size LCNF impure saves only
the signature persistently to the disk. This is possible because we no
longer have inlining/specialization at this point of compilation so all
we need is typing information (and potentially other environment
extensions) to guide our analyses.
This PR implements RFC #12216: native computation (`native_decide`,
`bv_decide`) is represented in the logic as one axiom per computation,
asserting the equality that was obtained from the native computation.
`#print axiom` will no longer show `Lean.trustCompiler`, but rather the
auto-generated names of these axioms (with, for example,
`._native.bv_decide.` in the name). See the RFC for more information.
This PR introduces a common MetaM helper (`nativeEqTrue`) used by
`native_decide` and `bv_decide` alike that runs the computation and then
asserts the result using an axiom.
It also deprecated the `ofReduceBool` axioms etc.
Not included in this PR is infrastructure for enumerating these axioms,
prettier `#print axioms` (should we want his) and tactic concurrency.
Fixes#12216.
This PR implements a cache for the positions of class universe level
parameters that only appear in output parameter types.
During type class resolution, the cache key for a query like
`HAppend.{0, 0, ?u} (BitVec 8) (BitVec 8) ?m` should be independent of
the specific metavariable IDs in output parameter positions. To achieve
this, output parameter arguments are erased from the cache key. However,
universe levels that only appear in output parameter types (e.g., `?u`
corresponding to the result type's universe) must also be erased to
avoid cache misses when the same query is issued with different universe
metavariable IDs.
This function identifies which universe level parameter positions are
"output-only" by collecting all level param names that appear in
non-output parameter domains, then returning the positions of any level
params not in that set.
**Remark**: This PR requires a manual update stage0 because it changes
the structure of our .olean files.
This PR refines upon #12106, by setting the `isRecursive` env extension
after adding the declaration, but before processing attributes like
`macro_inline` that want to look at the flag. Fixes#12268.
This PR avoids a potential deadlock on shutdown of a Lean program when
the number of pooled threads has temporarily been pushed above the
limit.
There's a potential race between the finalizer "waking up everyone"
after setting `m_shutting_down = true` and a worker that is about to be
throttled because of concurrency limits.
- `m_max_std_workers = 1`, `m_std_workers.size() = 2`, and the queue
still has tasks.
- Finalizer sets `m_shutting_down = true` and calls `notify_all()` while
a worker is running a task (outside of the mutex).
- Worker finishes a task, re-enters the loop, sees work, and "should
wait" because `active >= max`.
- Worker then calls `wait()` after the notify and never wakes, so
`join()` in the finalizer hangs.
This PR avoids the worker being blocked by not `wait()`ing if we are
already shutting down. The code is restructured a bit for readability,
where the first section is "there's no work in the queue" and the next
section is "there is some work in the queue"
This PR fixes a unification issue that appeared in
`Lean.Meta.MkIffOfInductiveProp` machinery that was upstreamed from
Mathlib. Inside of `toInductive`, wrong free variables were passed,
which made it impossible to perform a unification in certain cases.
Closes#12215
This PR provides more lemmas about sums of lists/arrays/vectors,
especially sums of `Nat` or `Int` lists/arrays/vectors.
This change has been motivated by my experience solving
`human-eval-lean` problems. Sums, minima and maxima are frequently
required and the improvements provided in this PR make it easier to
verify such programming tasks.
Changes:
* Added lemmas that `sum` equals `foldl`/`foldr`.
* Generalized `sum_append_nat` and `sum_reverse_nat` lemmas so that they
are polymorphic, requiring only some type class instances about the list
elements' type. The polymorphic lemmas aren't simp- or grind-annotated
because I fear the instance synthesis overhead. However, the `Nat` and
`Int` specializations are annotated (see below). Note that as
`{Array,Vector}.min` do not exist, some lemmas can't be stated and were
omitted.
* Added `List.min_singleton` and `List.max_singleton` lemmas as they
were needed for some proofs.
* `Nat`-related:
* Moved all `{List,Array,Vector}.sum` lemmas that are specific for `Nat`
into their own module: `Init.Data.List.Nat.Sum`, `Init.Data.Array.Nat`
and `Int.Data.Vector.Nat`.
* Notably, moved `Nat.sum_pos_iff_exists_pos` and renamed it to
`List.sum_pos_iff_exists_pos_nat`. This is more consistent and made it
possible to add `Array` and `Vector` variants of this lemma.
* Added lemmas proving that `l.sum / l.length` lies between the minimum
and the maximum of a list.
* Added analogous lemmas for `Int` lists/arrays/vectors to parallel
modules: `Init.Data.List.Int.Sum`, `Init.Data.Array.Int` and
`Int.Data.Vector.Int`.
* Renamed `sum_eq_sum_toList` to `sum_toList`, which better represents
the theorem's content.
This PR makes several small improvements to the list/array/vector API:
* It fixes typos in `Init.Core`.
* It adds `List.isSome_min_iff` and `List.isSome_max_iff`.
* It adds `grind` and `simp` annotations to various previously
unannotated lemmas.
* It adds lemmas for characterizing `∃ x ∈ xs, P x` using indices as `∃
(i : Nat), ∃ hi, P (xs[i])`, and similar universally quantified lemmas:
`exists_mem_iff_exists_getElem` and `forall_mem_iff_forall_getElem`.
* It adds `Vector.toList_zip`.
* It adds `map_ofFn` and `ofFn_getElem` for lists/arrays/vectors.
This PR adds the new transparency setting `@[instance_reducible]`. We
used to check whether a declaration had `instance` reducibility by using
the `isInstance` predicate. However, this was not a robust solution
because:
- We have scoped instances, and `isInstance` returns `true` only if the
scope is active.
- We have auxiliary declarations used to construct instances manually,
such as:
```lean
def lt_wfRel : WellFoundedRelation Nat
```
`isInstance` also returns `false` for this kind of declaration.
In both cases, the declaration may be (or may have been) used to
construct an instance, but `isInstance`
returns `false`. Thus, we claim it is a mistake to check the
reducibility status using `isInstance`.
`isInstance` indicates whether a declaration is available for the type
class resolution mechanism,
not its transparency status.
**We are decoupling whether a declaration is available for type class
resolution from its transparency status.**
**Remak**: We need a update stage0 to complete this feature.
---------
Co-authored-by: Sebastian Ullrich <sebasti@nullri.ch>
This PR fixes a bug on Windows with `IO.Process.spawn` where setting an
environment variable to the empty string would not set the environment
variable on the subprocess.
This PR adds the function `Std.Iter.isEmpty` and proves the
specification lemmas `Std.Iter.isEmpty_eq_match_step` and
`Std.Iter.isEmpty_toList` if the iterator is productive.
The monadic variant on `Std.IterM` is also provided.
This PR introduces projected minima and maxima, also known as
"argmin/argmax", for lists under the names `List.minOn` and
`List.maxOn`. It also introduces `List.minIdxOn` and `List.maxIdxOn`,
which return the index of the minimal or maximal element. Moreover,
there are variants with `?` suffix that return an `Option`. The change
further introduces new instances for opposite orders, such as
`LE.opposite`, `IsLinearOrder.opposite` etc. The change also adds the
missing `Std.lt_irrefl` lemma.
This PR ensures we cache the result of `unfold_definition` definition in
the kernel type checker. We used to cache this information in a thread
local storage, but it was deleted during the Lean 3 to Lean 4
transition.
This PR fixes a bug where `grind?` suggestions would not include
parameters using local variable dot notation (e.g.,
`cs.getD_rightInvSeq` where `cs` is a local variable). These parameters
were incorrectly filtered out because the code assumed all ident params
resolve to global declarations. In fact, local variable dot notation
produces anchors that need the original term to be loaded during replay,
so they must be preserved in the suggestion.
Closes#12185🤖 Prepared with Claude Code
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
This PR recognizes certain kinds of composite proof terms of the form
`hpre.trans hspec |> (wp prog).mono _ _ hpost` and abstracts them into
bespoke theorems. This should yield smaller proof terms. Sadly, kernel
checking time is unaffected, even regressing a bit. The number of shared
terms stays almost the same (+- a constant). Hence I deactivate the code
path in this patch. We keep the code, though, because it might be useful
in the future, also there are a few other improvements.
This PR gives a simpler semantics to `noncomputable`, improving
predictability as well as preparing codegen to be moved into a separate
build step without breaking immediate generation of error messages.
Specifically, `noncomputable` is now needed whenever an axiom or another
`noncomputable` def is used by a def except for the following special
cases:
* uses inside proofs, types, type formers, and constructor arguments
corresponding to (fixed) inductive parameters are ignored
* uses of functions marked `@[extern]/@[implemented_by]/@[csimp]` are
ignored
* for applications of a function marked `@[macro_inline]`,
noncomputability of the inlining is instead inspected
# Breaking change
After this change, more `noncomputable` annotations than before may be
required in exchange for improved future stability.
This PR adds a clone of the `mvcgen` tactic based on `SymM` and
evaluates it based on a ported `add_sub_cancel` benchmark. Notably, it
can reuse all the existing `@[spec]`-annotated theorems to generate VCs.
(It doesn't do control-flow splitting, simp rules on the program
expression or handling of lets; we'll get there.)
It is quite fast already, with the kernel being the bottle-neck:
```
goal_50: 69.524305 ms, kernel: 155.327778 ms
goal_100: 93.834221 ms, kernel: 407.370786 ms
goal_150: 131.364098 ms, kernel: 762.936720 ms
goal_200: 169.577172 ms, kernel: 1181.199093 ms
goal_250: 206.421738 ms, kernel: 1707.539380 ms
```
```
goal_200: 169.458637 ms, kernel: 1186.221085 ms
goal_400: 322.819718 ms, kernel: 3791.613854 ms
goal_600: 474.929013 ms, kernel: 7763.373757 ms
goal_800: 634.379422 ms, kernel: 13107.810430 ms
```
It is best compared to the `solveUsingSym <n> false true` measurements
of the SymM `add_sub_cancel` benchmark (`false`: without intermediate
eager simplification). For `n=200`, it reports
```
goal_200: 779.482300 ms, kernel: 742.097404 ms
```
suggesting that the generated proof term could be improved for kernel
reduction. (TODO.)
I'm unsure whether `solveUsingSym` is run in interpreted mode, so take
the >400% speedup with a grain of salt.
We can definitely conclude that VC generation time is currently not a
bottleneck compared to kernel checking time.
Plot for discharging goals of sizes 100..800:
<img width="1000" height="600" alt="Code_Generated_Image(1)"
src="https://github.com/user-attachments/assets/90e76a45-fa46-4d02-912a-c3355e2aa094"
/>
Plot comparing Kernel and Goal time:
<img width="1000" height="600" alt="Code_Generated_Image(2)"
src="https://github.com/user-attachments/assets/5849ba0f-1d83-4f2d-98dd-fa65b840bb4e"
/>
This PR introduces the defining equality `Triple.iff` and uses that in
proofs instead of relying on definitional equality. It also introduces
`Triple.iff_conseq` that is useful for backward reasoning and introduces
verification conditions. Similarly, `Triple.entails_wp_*` theorems are
introduced for backward reasoning where the target is an stateful
entailment rather than a triple.
This PR introduces a phase separation to the LCNF IR. This is a
preparation for the merge of
the old `Lean.Compiler.IR` and the new `Lean.Compiler.LCNF` framework.
The change parametrizes all relevant `LCNF` data structures over a
`Purity` parameter and
additionally carries around proofs that the `Purity` has certain values,
depending on what's
required. This is done as opposed to indexing the types over `Purity`
because we do (almost) never
have to store the `Purity` value for phase generic structures this way.
This PR reverts a lot of the changes done in #8308. We practically
encountered situations such as:
```
fun y (z) :=
let x := inst
mkInst x z
f y
```
Where the instance puller turns it into:
```
let x := inst
fun y (z) :=
mkInst x z
f y
```
The current heuristic now discovers `x` being in scope at the call site
of `f` and being used under a binder in `y` and thus blocks pulling in
`x` to the specialization, abstracting over an instance.
According to @zwarich this was done at the time either due to observed
stack overflows or pulling in computation into loops. With the current
configuration for abstraction in specialization it seems rather unlikely
that we pull in a non trivial computation into a loop with this. We also
practically didn't observe stack overflows in our tests or benchmarks.
Cameron speculates that the issues he observed might've been fixed
otherwise by now.
Crucial note: Deciding not to abstract over ground terms *might* cause
us to pull in computationally intensive ground terms into a loop. We
could decide to weaken this to just instance terms though of course even
computing instances might end up being non-trivial.
This PR provides `Array` operations analogous to `List.min(?)` and
`List.max(?)`.
I had to prove a few auxiliary lemmas. Downstream in Batteries, which
already had `List.min` and `List.max`, I renamed their variants to
`List.rangeMin` and `List.rangeMax` in the PR testing branch. Their
version is more general in the sense that it has `start` and `stop`
autoParams, like `Array.foldl` has, but I think the futore belongs to
`Subarray.min` instead (which I haven't implemented yet).
This PR updates docstrings and function signatures in order to complete
the transition from `Iter.Partial` to `Iter.Total` (extrinsically
terminating by default). It also deprecates `allowNontermination` and
adds `Iter.Total.atIdxSlow?`.
This PR ensures `dsimp` does not "simplify" instances by default. The
old behavior can be retrieved by using
```
set_option backward.dsimp.instances true
```
Applying `dsimp` to instances creates non-standard instances, and this
creates all sorts of problems in Mathlib.
This modification is similar to
```
set_option backward.dsimp.proofs true
```
---------
Co-authored-by: Kim Morrison <kim@tqft.net>
Co-authored-by: Claude <noreply@anthropic.com>
This PR documents the available `changelog-*` labels and when to use
them in the project-specific CLAUDE.md instructions.
🤖 Prepared with Claude Code
Co-authored-by: Claude <noreply@anthropic.com>
This PR fixes `Init.Data.Dyadic.Instances` and `Init.Data.Dyadic.Inv`.
Previously, all declarations defined in boths file were private and not
exposed.
This PR fixes how we determine whether a function parameter is an
instance.
Previously, we relied on binder annotations (e.g., `[Ring A]` vs `{_ :
Ring A}`)
to make this determination. This is unreliable because users
legitimately use
`{..}` binders for class types when the instance is already available
from
context. For example:
```lean
structure OrdSet (α : Type) [Hashable α] [BEq α] where
...
def OrdSet.insert {_ : Hashable α} {_ : BEq α} (s : OrdSet α) (a : α) : OrdSet α :=
...
```
Here, `Hashable` and `BEq` are classes, but the `{..}` binder is
intentional, the
instances come from `OrdSet`'s parameters, so type class resolution is
unnecessary.
The fix checks the parameter's *type* using `isClass?` rather than its
syntax, and
caches this information in `FunInfo`. This affects several subsystems:
- **Discrimination trees**: instance parameters should not be indexed
even if marked with `{..}`
- **Congruence lemma generation**: instances require special treatment
- **`grind` canonicalizer**: must ensure canonical instances
**Potential regressions**: automation may now behave differently in
cases where it
previously misidentified instance parameters. For example, a rewrite
rule in `simp` that was
not firing due to incorrect indexing may now fire.
---------
Co-authored-by: Kim Morrison <kim@tqft.net>
Co-authored-by: Claude <noreply@anthropic.com>
Due to the way variable expansion and if interact in cmake, unquoted
variable expansions should essentially never be used inside if and may
lead to unexpected behavior. Also, quoted variable expansions can
usually be replaced by the unquoted variable name.
For more details, see this section in the cmake docs:
https://cmake.org/cmake/help/latest/command/if.html#variable-expansion
As one example of the kinds of issues that can occur with unquoted
variable expansions, consider this check from
`src/shell/CMakeLists.txt`, which tries to ensure that a test is only
run in non-WASM builds.
```cmake
if(NOT ${EMSCRIPTEN})
```
If the variable `EMSCRIPTEN` is empty or not defined (as is the case in
a non-WASM build), `${EMSCRIPTEN}` expands to 0 arguments, meaning the
check becomes
```cmake
if(NOT)
```
Since the `NOT` is unquoted, the if now tries to resolve it as a
variable. Since the variable `NOT` does not exist, the condition is
false and the test is never executed, even in non-WASM builds.
This PR provides the `Nat`/`Int` lemmas `x ≤ y * z ↔ (x + z - 1) / z ≤
y`, `x ≤ y * z ↔ (x + y - 1) / y ≤ z` and `x / z + y / z ≤ (x + y) / z`.
The PR is inspired by a `human-eval-lean` problem, the solution of which
required these lemmas.
This PR adds the `introSubstEq` MetaM tactic, as an optimization over
`intro h; subst h` that avoids introducing `h : a = b` if it can be
avoided,
which is the case when `b` can be reverted without reverting anything
else. Speeds up the generation of `injEq` theorem.
This PR removes the LCNF testing framework. Unfortunately it never got
used much and porting it to
the extended LCNF structure now would be a bit of effort that would
ultimately be in vain.
This PR fixes a bug in `System.Uri.fileUriToPath?` where it wouldn't use
the default Windows path separator in the path it produces.
It also adjusts the URI patching in the interactive test runner to be
more robust.
This PR adds `mkBackwardRuleFromExpr` to create backward rules from
expressions, complementing the existing `mkBackwardRuleFromDecl` which
only works with declaration names.
The new function enables creating backward rules from partially applied
terms. For example, `mkBackwardRuleFromExpr (mkApp (mkConst
``Exists.intro [1]) Nat.mkType)` creates a rule for `Exists.intro` with
the type parameter fixed to `Nat`, leaving only the witness and proof as
subgoals.
The `levelParams` parameter supports universe polymorphism: when
creating a rule like `Prod.mk Nat` that should work at multiple universe
levels, the caller specifies which level parameters remain polymorphic.
The pattern's universe variables are then instantiated appropriately at
each application site.
Also refactors `Pattern.lean` to share code between declaration-based
and expression-based pattern creation, extracting `mkPatternFromType`
and `mkEqPatternFromType` as common helpers.
This PR adds theorems showing the consistency between `find?` and the
various index-finding functions. The theorems establish bidirectional
relationships between finding elements and finding their indices.
**Forward direction** (find? in terms of index):
- `find?_eq_map_findFinIdx?_getElem`: `xs.find? p = (xs.findFinIdx?
p).map (xs[·])`
- `find?_eq_bind_findIdx?_getElem?`: `xs.find? p = (xs.findIdx? p).bind
(xs[·]?)`
- `find?_eq_getElem?_findIdx`: `xs.find? p = xs[xs.findIdx p]?`
**Reverse direction** (index in terms of find?):
- `findIdx?_eq_bind_find?_idxOf?`: `xs.findIdx? p = (xs.find? p).bind
(xs.idxOf?)`
- `findFinIdx?_eq_bind_find?_finIdxOf?`: `xs.findFinIdx? p = (xs.find?
p).bind (xs.finIdxOf?)`
- `findIdx_eq_getD_bind_find?_idxOf?`: `xs.findIdx p = ((xs.find?
p).bind (xs.idxOf?)).getD xs.length`
All theorems are provided for `List`, `Array`, and `Vector` (where
applicable).
Requested at
https://leanprover.zulipchat.com/#narrow/channel/113488-general/topic/show.20that.20Array.2Efind.3F.20and.20Array.2EfindFinIdx.3F.20consistent/near/567340199🤖 Prepared with Claude Code
Co-authored-by: Claude <noreply@anthropic.com>
This PR activates `getElem?_pos` more aggressively, triggered by `c[i]`.
- [x] depends on: #12176🤖 Prepared with Claude Code
---------
Co-authored-by: Claude <noreply@anthropic.com>
This PR fixes an issue where PR releases were not created when the test
suite failed, even though the build artifacts were available. The
workflow now runs whenever a PR's CI completes, regardless of
success/failure, and relies on the artifact verification step to ensure
the necessary build artifacts exist before proceeding.
This allows developers to get PR toolchains and test against Mathlib
even when the Lean test suite has failures, as long as the build jobs
succeeded.
🤖 Prepared with Claude Code
Co-authored-by: Claude <noreply@anthropic.com>
This PR fixes a bug where delayed E-match theorem instances could cause
uniqueId collisions in the instance tracking map.
The `uniqueId` for theorem instances is generated using `numInstances`,
but this counter was only bumped for immediately activated instances
(`.ready` case), not for delayed instances (`.next` case). This caused
ID collisions:
1. Theorem A matches, becomes delayed, gets `uniqueId = N`
2. Counter isn't bumped (stays at N)
3. Theorem B matches next, gets `uniqueId = N` (same!)
4. B's entry overwrites A's entry in `instanceMap`
5. A's tracking is lost
This manifested as `grind?` and `finish?` producing `instantiate approx`
(meaning "we couldn't determine which theorems to use") instead of
proper `instantiate only [...]` with specific theorem lists.
The fix bumps `numInstances` for delayed instances too, ensuring each
theorem instance gets a truly unique ID.
🤖 Prepared with Claude Code
Co-authored-by: Claude <noreply@anthropic.com>
This PR adds `prefix_map_iff_of_injective` and
`suffix_map_iff_of_injective` lemmas to Init.Data.List.Nat.Sublist.
These lemmas establish that if a function `f` is injective, then the
prefix and suffix relations are preserved under mapping (e.g., `l₁.map f
<+: l₂.map f ↔ l₁ <+: l₂`). These additions complement the existing
index-based lemmas in this file and allow for simpler structural proofs
without resorting to `take`, `drop`, or manual index manipulation.
This PR adds the function `Std.Iter.first?` and proves the specification
lemma `Std.Iter.first?_eq_match_step` if the iterator is productive.
The monadic variant on `Std.IterM` is also provided.
We use this new function to fix the default implementation for
`startsWith` and `dropPrefix` on `String` patterns, which used to fail
if the searcher returned a `skip` at the beginning. None of the patterns
we ship out of the box were affected by this, but user-defined patterns
were vulnerable.
---------
Co-authored-by: Paul Reichert <6992158+datokrat@users.noreply.github.com>
This PR adds regression tests that catch issues where structures/classes
with class-typed fields produce HEq goals in `congr` instead of handling
Prop fields automatically.
Both tests pass on v4.28.0-rc1 (before isInstance detection changes).
## Test 1: Structure extending classes (mirrors Mathlib's GroupTopology)
```lean
structure MyGroupTopology (α : Type) extends MyTopology α, IsContinuousMul α
theorem MyGroupTopology.toMyTopology_injective {α : Type} :
Function.Injective (MyGroupTopology.toMyTopology : MyGroupTopology α → MyTopology α) := by
intro f g h
cases f
cases g
congr
```
**Failure mode:** `⊢ toIsContinuousMul✝¹ ≍ toIsContinuousMul✝`
## Test 2: Class with explicit class-typed field (mirrors Mathlib's
PseudoEMetricSpace)
```lean
class MyMetricSpace (α : Type) extends MyDist α where
dist_self : ∀ x : α, dist x x = 0
toMyUniformity : MyUniformity α -- explicit class-typed field (NOT from extends)
uniformity_dist : toMyUniformity.uniformity (fun x y => dist x y = 0)
protected theorem MyMetricSpace.ext {α : Type} {m m' : MyMetricSpace α}
(h : m.toMyDist = m'.toMyDist) (hU : m.toMyUniformity = m'.toMyUniformity) : m = m' := by
cases m
cases m'
congr 1 <;> assumption
```
**Failure mode:** `⊢ dist_self✝¹ ≍ dist_self✝` and `⊢ uniformity_dist✝¹
≍ uniformity_dist✝`
## Context
These tests are related to #12172, which changes instance parameter
detection from binder-based to `isClass?`-based. That change can affect
how structure fields are classified in congruence lemma generation.
🤖 Prepared with Claude Code
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
This PR clarifies the release notes title format in the release
checklist documentation.
**Changes:**
- Add explicit section explaining title format for -rc1, subsequent RCs,
and stable releases
- Make it clear that titles should include both the RC suffix AND the
date (e.g., "Lean 4.7.0-rc1 (2024-03-15)")
- Update example to use realistic date format instead of YYYY-MM-DD
- Clarify that only content is written for -rc1, subsequent releases
just update the title
This addresses confusion about whether RC release notes should include
the date in the title.
---------
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
This PR documents an issue encountered during the v4.28.0-rc1 release:
if release notes are merged to the reference-manual repository AFTER the
version tag is created, the deployed documentation won't include them.
The fix is to either:
1. Include release notes in the same PR as the toolchain bump (or merge
before tagging)
2. Regenerate the tag after merging release notes
🤖 Prepared with Claude Code
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
This PR switches the PR release workflow from
`softprops/action-gh-release` to `gh release create`.
The `softprops/action-gh-release` action enumerates all releases to
check for existing ones, which fails when the repository has more than
10000 releases due to GitHub API pagination limits. The
`lean4-pr-releases` repository has accumulated over 10000 releases,
causing the PR release workflow to fail with:
```
Only the first 10000 results are available.
```
This is currently blocking all PR toolchain releases, including
https://github.com/leanprover/lean4/pull/12175.
🤖 Prepared with Claude Code
---------
Co-authored-by: Claude <noreply@anthropic.com>
This PR fixes a comment that said "implicit arguments" when the code
actually checks `isInstImplicit`, which is specifically for instance
implicit arguments (`[...]` binders), not all implicit arguments.
🤖 Prepared with Claude Code
Co-authored-by: Claude <noreply@anthropic.com>
This PR bumps the version to 4.29.0 to begin the next development cycle
after v4.28.0-rc1.
🤖 Prepared with Claude Code
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
This PR adds two benchmarks for mvcgen in the style of Leo's SymM
benchmarks.
While performance on add_sub_cancel_StateM.lean is in the same order of
magnitude as the corresponding MetaM benchmark, add_if_sub_StateM.lean
is far slower.
Measurements for add_sub_cancel:
```
goal_10: 245.576221 ms, kernel: 134.134182 ms
goal_20: 613.945320 ms, kernel: 115.453811 ms
goal_30: 1074.053596 ms, kernel: 179.076070 ms
goal_40: 1680.678302 ms, kernel: 252.066677 ms
goal_50: 2457.209584 ms, kernel: 293.974096 ms
goal_60: 3271.773330 ms, kernel: 368.394386 ms
goal_70: 3981.247921 ms, kernel: 434.297822 ms
goal_80: 5077.300540 ms, kernel: 507.047772 ms
goal_90: 6486.990060 ms, kernel: 556.952095 ms
goal_100: 7791.399986 ms, kernel: 623.605163 ms
```
Measurements for add_if_sub:
```
goal_2: 89.762349 ms, kernel: 43.320205 ms
goal_3: 190.655546 ms, kernel: 38.888499 ms
goal_4: 434.461936 ms, kernel: 75.234581 ms
goal_5: 1110.295284 ms, kernel: 161.698707 ms
goal_6: 3241.383031 ms, kernel: 326.137173 ms
goal_7: 11675.609970 ms, kernel: 684.907188 ms
```
Much room for improvement.
This PR adds `Option.of_wp_eq` and `Except.of_wp_eq`, similar to the
existing `Except.of_wp`. `Except.of_wp` is deprecated because applying
it requires prior generalization, at which point it is more convenient
to use `Except.of_wp_eq`.
This PR makes the compiler produce C code that statically initializes
close terms when possible. This change reduces startup time as the terms
are directly stored in the binary instead of getting computed at
startup.
The set of terms currently supported by this mechanism are:
- string literals
- ctors called with other statically initializeable arguments
- `Name.mkStrX` and other `Name` ctors as they require special support
due to their computed field and occur frequently due to name literals.
In core there are currently 152,524 closed terms and of these 103,929
(68%) get initialized statically with this PR. The remaining 48585 ones
are not extracted because they use (potentially transitively) various
non trivial pieces of code like `stringToMessageData` etc. We might
decide to add special support for these in the future but for the moment
this feels like it's overfitting too much for core.
This extracts a `postCallback` helper so that only the actual callback
is inlined.
Part of the motivation here is to exclude these tracing frames from
flame graph profiles.
---------
Co-authored-by: Sebastian Ullrich <sebasti@nullri.ch>
This PR documents the release notes writing process in detail and adds a
guard check to `release_checklist.py` to ensure release notes are
created for `-rc1` releases before proceeding with downstream repository
updates.
- **doc/dev/release_checklist.md**: Expanded "Writing the release notes"
section with detailed steps for generating, reviewing, and formatting
release notes in Verso format
- **script/release_checklist.py**: Added
`check_release_notes_file_exists()` to verify the release notes file
exists in reference-manual repository
- **.claude/commands/release.md**: Added "Release Notes" section
explaining the process for creating release notes during `-rc1` releases
🤖 Prepared with Claude Code
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
verso depends on plausible, but this wasn't recorded in
release_repos.yml. This caused the release checklist to not properly
track the dependency ordering.
This PR adds `simpTelescope`, a simproc that simplifies telescope
binders (`have`-expression values and arrow hypotheses) but not the
final body. This is useful for simplifying targets before introducing
hypotheses.
This PR adds `simpArrowTelescope`, a simproc that simplifies telescopes
of non-dependent arrows (p₁ → p₂ → ... → q) while avoiding quadratic
proof growth.
When using `Expr.forallE` to represent nested implications, each nesting
level bumps de Bruijn indices in subterms, destroying sharing even with
hash-consing. For example, a free variable `x` gets different de Bruijn
representations at each depth, causing proof terms to grow.
`simpArrowTelescope` works by:
- Converting arrows to `Arrow p q` (a definitional wrapper)
- Simplifying each component
- Converting back to `→` form
Since `Arrow` arguments are not under binders, subterms remain identical
across nesting levels and can be shared.
The `simp_4` benchmark demonstrates the improvement:
With `forallE`: ~160ms, proof_size ≈ 173k
With `Arrow`: ~43ms, proof_size ≈ 16k
Tradeoff: `simpArrowTelescope` misses simplifications that depend on the
arrow structure (e.g., `p → p` to `True`), since post-methods aren't
applied to intermediate arrows. Thus, it is not used by default. to use
it, one has to set `simpArrowTelescope` as a `pre`-method.
This PR reverts #12000, which introduced a regression where `simp`
incorrectly rejects valid rewrites for perm lemmas.
The issue is that `NameGenerator.mkChild` creates names that don't
maintain the ordering assumption used by `acLt` for perm lemma
decisions. For example, after the change:
- Child generator creates names like `_uniq.102.2`
- Parent continues with `_uniq.7`
- But `Name.lt (.num (.num `_uniq 102) 2) (.num `_uniq 7)` is true
This causes fvars created later (in async tasks) to compare as smaller
than fvars created earlier, breaking the assumption that later fvars
compare greater according to `Name.lt`.
Fixes#12136.
🤖 Prepared with [Claude Code](https://claude.com/claude-code)
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
This PR adds an API for building symbolic simulation engines and
verification
condition generators that leverage `grind`. The API wraps `Sym`
operations to
work with `grind`'s `Goal` type, enabling lightweight symbolic execution
while
carrying `grind` state for discharge steps.
New operations on `Goal`:
- `mkGoal`: create a `Goal` from an `MVarId`
- `introN`, `intros`: introduce binders
- `apply`: apply backward rules
- `simp`, `simpIgnoringNoProgress`: simplify using `Sym.Simp`
- `internalize`, `internalizeAll`: add hypotheses to the E-graph
- `grind`: attempt to close the goal using `grind`
- `assumption`: close by matching a hypothesis
A new test demonstrates the API on a stateful program with conditionals,
using `grind` to discharge arithmetic side conditions.
This PR fixes a bug introduced in #12086 where a `lake build :release
--no-build` would exit with code 1 rather than the `--no-build ` code 3.
Now both the bug from #12086 and this bug are fixed.
This PR adds a new benchmark `shallow_add_sub_cancel.lean` that
demonstrates symbolic simulation using a shallow embedding into monadic
`do` notation, as opposed to the deep embedding approach in
`add_sub_cancel.lean`.
The shallow embedding approach:
- Uses Lean's `StateM` monad directly instead of a custom command
language
- Defines `Exec s k post` as a simple predicate: `post (k s).1 (k s).2`
- Proves helper theorems for reasoning about monadic operations (`pure`,
`bind`, `get`, `set`, `modify`, `ite`)
- Programs are written in actual `do`-notation rather than a custom AST
The benchmark solves goals using both the `MetaM` and `SymM` frameworks,
showing that the shallow embedding integrates well with the symbolic
simulation infrastructure. `SymM` is again way faster than `MetaM`
### Symbolic simulation benchmark — tactic time only
Problem size `n` corresponds to a program with `4·n` monadic actions.
| n | MetaM tactic (ms) | SymM tactic (ms) | Speedup |
|-----|-------------------|------------------|---------|
| 10 | 82.10 | 11.37 | ~7.2× |
| 20 | 176.21 | 17.71 | ~9.9× |
| 30 | 306.47 | 25.39 | ~12.1× |
| 40 | 509.52 | 34.53 | ~14.7× |
| 50 | 689.19 | 43.51 | ~15.8× |
| 60 | 905.86 | 52.47 | ~17.3× |
| 70 | 1172.31 | 62.50 | ~18.8× |
| 80 | 1448.48 | 70.65 | ~20.5× |
| 90 | 1787.15 | 80.89 | ~22.1× |
| 100 | 2128.12 | 90.77 | ~23.5× |
<img width="580" height="455" alt="image"
src="https://github.com/user-attachments/assets/3511aaab-4d53-4520-8302-65d2d100df4a"
/>
This PR fixes a bug in the CI version validation where `grep -oE
'[0-9]+'` matches
multiple numbers from the comment on the same line:
```
set(LEAN_VERSION_IS_RELEASE 1) # This number is 1 in the release revision, and 0 otherwise.
```
The grep extracts `1`, `1`, and `0`, causing the comparison to fail.
🤖 Prepared with Claude Code
This PR adds a check to the release checklist script that verifies the
reference-manual release notes title matches the release type:
- For RC releases (e.g., v4.27.0-rc1): verifies the title contains the
exact
RC suffix (e.g., "Lean 4.27.0-rc1")
- For final releases (e.g., v4.27.0): verifies the title does NOT
contain
any "-rc" suffix (e.g., "Lean 4.27.0")
The check looks at the PR branch (bump_to_vX.Y.Z) for the release notes
file
at `Manual/Releases/v4_X_Y.lean` and parses the `#doc (Manual) "Lean
..."` line.
🤖 Prepared with Claude Code
---------
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
This PR adds documentation about the nightly build infrastructure to the
`/release` command to help future release managers understand the
relationship between branches and tags:
- `nightly` and `nightly-with-mathlib` are **branches** in
`leanprover/lean4`
- Dated tags like `nightly-YYYY-MM-DD` are **tags** in
`leanprover/lean4-nightly`
- When a nightly succeeds with mathlib, all three should point to the
same commit
🤖 Prepared with Claude Code
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
This PR fixes an issue that may sporadically trigger ASAN to got into a
deadlock when running a subprocess through the `IO.Process.spawn`
framework.
The general issue here is that we run `fork()` and then perform an
allocation in the child before going to `execvp` (for allocating the
arguments to `execvp`). As it turns out, doing this can cause a race
condition in ASAN that ultimately causes a deadlock in the child. This
was fixed upstream but then rolled back (see
https://github.com/google/sanitizers/issues/774). Thus, we must avoid
allocating any memory in between `fork` and `execvp`.
This PR fixes the verso hint that appears when using `sorry` in an
example block. It previously said: `` The `+error` flag indicates that
warnings are expected: +warning `` This PR replaces `error` with
`warning`. Fixes#12064
This PR revives the ability to specify modules in dependencies via the
basic `+mod` target key.
Implementation-wise, this removes deprecation of `BuildKey.module` and
once again uses it for `+mod` target keys. It also adds a test for
depending on a module of a dependency via `needs`.
This PR fixes the `lake query` output for targets which produce an
`Array` or `List` of a value with a custom `QueryText` or `QueryJson`
instance (e.g., `deps` and `transDeps`).
The most important change is that all bench scripts now must always
output to `measurements.jsonl` instead of being allowed to output
results on stdout/err.
This PR implements iteration over ranges for `Fin` and `Char`.
To this end, we introduce machinery for pulling back lawfulness of
`UpwardEnumerable` along an injective map and study the function
`Char.ordinal : Char -> Fin Char.numCodePoints`.
This PR fixes two Lake cache issues: a bug where a failed upload would
not produce an error and a mistake in the `--wfail` checks of the cache
commands.
This PR adds a comparison between `MetaM` and `SymM` for a benchmark was
proposed during the Lean@Google Hackathon.
### Benchmark description
In this benchmark, we define the semantics of a very simple imperative
language using an inductive predicate
```
Exec prog events mem lctx post
```
The predicate holds if, when executing the program `prog` with an
initial list of events `events`, memory `mem`, and local context `lctx`,
the postcondition `post` holds.
We then consider the following program:
```
input b
a := b
a := a + a
a := a - b
...
a := a + a
a := a - b
```
That is, after reading an input value `b`, the program repeatedly
updates the variable `a` by doubling it and then subtracting `b`.
We prove that, for any initial memory `m` and local context `l`, and
starting from the empty list of events, the following postcondition
holds:
```
fun t' m' l' =>
m' = m ∧ -- memory did not change
∃ v : Word,
t' = [IOEvent.IN v] ∧ -- exactly one input event
l'.get "a" = some v -- `a` contains the input value
```
In other words, executing the program produces exactly one input event,
leaves the memory unchanged, and ensures that the final value of `a` is
equal to the input value.
### Symbolic simulation benchmark (problem size `n`, with `2·n + 2`
instructions)
| Problem size (n) | MetaM time (ms) | MetaM kernel (ms) | SymM time
(ms) | SymM kernel (ms) | Total speedup |
|------------------|------------------|-------------------|----------------|------------------|---------------|
| 10 | 94.83 | 6.60 | 7.04 | 6.18 | ~13.5× |
| 20 | 218.92 | 13.33 | 14.15 | 13.02 | ~15.5× |
| 30 | 375.10 | 22.95 | 26.51 | 19.81 | ~14.2× |
| 40 | 563.82 | 34.99 | 40.42 | 29.55 | ~14.0× |
| 50 | 815.89 | 53.78 | 60.84 | 42.25 | ~13.4× |
| 60 | 1081.09 | 73.46 | 80.99 | 53.52 | ~13.3× |
| 70 | 1400.80 | 102.70 | 106.02 | 68.61 | ~13.2× |
| 80 | 1772.19 | 126.65 | 134.23 | 87.64 | ~13.2× |
| 90 | 2203.41 | 161.68 | 168.26 | 115.52 | ~13.1× |
| 100 | 2474.09 | 191.23 | 209.13 | 143.86 | ~11.8× |
<img width="580" height="455" alt="image"
src="https://github.com/user-attachments/assets/bc7058fa-e71a-4c2c-be28-860f39166965"
/>
### Symbolic simulation with extra simplification (SymM)
Problem size `n` corresponds to a program with `2·n + 2` instructions.
| n | Total time (ms) | Kernel time (ms) | Non-kernel time (ms) |
|-----|------------------|------------------|----------------------|
| 10 | 6.33 | 3.97 | 2.36 |
| 20 | 10.30 | 5.59 | 4.71 |
| 30 | 13.72 | 7.38 | 6.34 |
| 40 | 17.85 | 8.84 | 9.01 |
| 50 | 21.90 | 10.63 | 11.27 |
| 60 | 27.00 | 12.56 | 14.44 |
| 70 | 32.02 | 14.04 | 17.98 |
| 80 | 37.25 | 15.76 | 21.49 |
| 90 | 42.55 | 17.95 | 24.60 |
| 100 | 49.30 | 20.03 | 29.27 |
| 200 | 125.56 | 38.21 | 87.36 |
| 300 | 293.58 | 66.79 | 226.79 |
| 400 | 361.87 | 78.96 | 282.91 |
| 500 | 518.51 | 102.51 | 416.00 |
| 600 | 716.63 | 122.81 | 593.82 |
This PR fixes a bug where a `lake build --no-build` would exit with code
`3` if the optional job to fetch a GitHub or Reservoir release for a
package failed (even if nothing else needed rebuilding).
This PR fixes the procedure for finding the mangled symbol name of boxed
variants of native functions. Previously, the wrong symbol name has been
used for names ending in `_`: For example `test_` mangles to `l_test__`
but `test_._boxed` mangles to `l_test___00__boxed`, not
`l_test_____boxed` which the compiler would previously wrongly use.
This probably didn't affect anybody though since the failure condition
is pretty rare: the name of a native function that the interpreter tries
to execute would've had to end in `_`.
This PR adds the debugging helper functions `Expr.checkMaxShared` and
`MVarId.checkMaxShared` to `Sym`, and fixes a bug when visiting
telescopes in `Sym.simp`.
This PR adds additional debugging information to a run of `lake build
--no-build` via a `.nobuild` trace file. When a build fails due to
needing a rebuild, Lake emits the new expected trace next as `.nobuild`
file next to the build's old `.trace`. The inputs recorded in these
files can then be compared to debug what caused the mismatch.
To help keep the build directory clean, the `.nobuild` trace file is
removed on the next successful build.
This PR makes the automatic first token detection in tactic docs much
more robust, in addition to making it work in modules and other contexts
where builtin tactics are not in the environment. It also adds the
ability to override the tactic's first token as the user-visible name.
Previously, first token detection would look up the parser descriptor in
the environment and process its syntax. This would be incorrect for
builtin parsers, as well as for modules in which the definition is not
loaded. Now, it instead consults the Pratt parsing table for the
`tactic` syntax category. Tests are added that ensure this keeps working
in modules, and also that the first token of all tactics that ship with
Lean are either detected unambiguously or annotated to remove ambiguity.
Closes#12038.
This PR fixes a bug where the unknown identifier code actions were
broken in NeoVim due to the language server not properly setting the
`data?` field for all code action items that it yields.
This PR adds support for offset terms in `SymM`. This is essential for
handling equational theorems for functions that pattern match on natural
numbers in `Sym.simp`. Without this, it cannot handle simple examples
such as
```lean
def pw (n : Nat) : Nat :=
match n with
| 0 => 1
| n+1 => 2 * pw n
example : pw 4 = 16 := by
sym_simp [pw.eq_1, pw.eq_2]
example : pw (a + 2) = 2 * (2 * pw a) := by
sym_simp [pw.eq_2]
```
This PR adds `lake shake` as a built-in Lake command, moving the shake
functionality from `script/Shake.lean` into the Lake CLI.
## Motivation
Per discussion with @Kha and @tydeu, having shake as a top-level Lake
command is preferable to `lake exe shake` because:
- Avoids the awkwardness of accessing core tools via `lake exe`
- Compiles shake into the Lake binary, avoiding lakefile issues
- No benefit to lazy compilation on user machines for this tool
## Changes
- Move shake logic from `script/Shake.lean` to
`src/lake/Lake/CLI/Shake.lean`
- Add `lake shake` command dispatch in `Lake/CLI/Main.lean`
- Add help text in `Lake/CLI/Help.lean`
- Remove the standalone shake executable from `script/lakefile.toml`
## Usage
```
lake shake [OPTIONS] [<MODULE>...]
```
See `lake shake --help` for full documentation.
🤖 Prepared with Claude Code
---------
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: Mac Malone <mac@lean-fro.org>
Co-authored-by: Sebastian Ullrich <sebasti@nullri.ch>
This PR moves `String.ofList` to `Init.Prelude`. It is a function that
the Lean kernel expects to be present and has special support for (when
reducing string literals). By moving this to `Init.Prelude`, all
declarations that are special to the kernel are in that single module.
After #12001, it was no longer true that `lean_trace(name(...), ...)`
would only perform the name allocation if no trace option was set. This
PR instead avoids the allocation in any case by avoiding this pattern.
This PR changes the default of `enableArtifactCache` to use the
workspace's `enableArtifactCache` setting if the package is a dependency
and `LAKE_ARTIFACT_CACHE` is not set. This means that dependencies of a
project with `enableArtifactCache` set will also, by default, use Lake's
local artifact cache.
This PR adds `simpControl`, a simproc that handles control-flow
expressions such as `if-then-else`. It simplifies conditions while
avoiding unnecessary work on branches that won't be taken.
The key behavior of `simpControl`:
- Simplifies the condition of `if-then-else` expressions
- If the condition reduces to `True` or `False`, returns the appropriate
branch, and continue simplifying.
- If the condition simplifies to a new expression, rebuilds the
`if-then-else` with the simplified condition (synthesizing a new
`Decidable` instance), and mark it as "done". That is, simplifier main
loop will not visit branches.
- Does **not** visit branches unless the condition becomes `True` or
`False`
This is useful for symbolic simplification where we want to avoid
wasting effort
simplifying branches that may be eliminated after the condition is
resolved.
This PR also fixes a bug in `Sym/Simp/EvalGround.lean`, and adds some
helper functions.
This PR adds `Sym.Simp.evalGround`, a simplification procedure for
evaluating ground terms of builtin numeric types. It is designed for
`Sym.simp`.
Key design differences from `Meta.Simp` simprocs:
- Pure value extraction: `getValue?` functions are `OptionT Id` rather
than
`MetaM`, avoiding `whnf` overhead since `Sym` maintains canonical forms
- Specialized predicate lemmas: comparisons use pre-proved lemmas like
`Int.lt_eq_true` applied with `rfl`, avoiding `Decidable` instance
reconstruction at each call site
- Type dispatch via `match_expr`: assumes standard instances, no
synthesis
Supported types: `Nat`, `Int`, `Rat`, `Fin n`, `BitVec n`,
`UInt8/16/32/64`,
`Int8/16/32/64`.
Supported operations: arithmetic (`+`, `-`, `*`, `/`, `%`, `^`), bitwise
(`&&&`, `|||`, `^^^`, `~~~`), shifts (`<<<`, `>>>`), comparisons (`<`,
`≤`,
`>`, `≥`, `=`, `≠`, `∣`), and boolean predicates (`==`, `!=`).
This PR fixes an issue where attributes like `@[irreducible]` would not
be allowed under the module system unless combined with `@[exposed]`,
but the former may be helpful without the latter to ensure downstream
non-`module`s are also affected.
Fixes#12025
Drastically speeds up `isTracingEnabledFor` in the common case, which
has evolved from "no options set" to "`Elab.async` and probably some
linter options set but no `trace`".
## Breaking changes
`Lean.Options` is now an opaque type. The basic but not all of the
`KVMap` API has been redefined on top of it.
Ensure that individual definitions known statically to be unreachable
are stripped out by the linker instead of only whole modules. Achieves
sizeable savings today and will do more so with upcoming module system
compilation refinements.
This PR allows 'Go to Definition' to look through reducible definition
when looking for typeclass instance projections.
Specifically, this means that using 'Go to Definition' on uses of
`GT.gt` will now yield the corresponding `LT` instance as well.
This PR fixe a superliniear behavior in the closed subterm extractor.
Consider an LCNF of the shape:
```
let x1 := f arg
let x2 := f x1
let x3 := f x2
let x4 := f x3
...
```
In this case the previous closed term extraction algorithm would visit
`x1`, then `x2` and `x1`,
then `x3`,`x2`,`x1` and so on, failing each time. We now introduce a
cache to avoid this behavior.
This PR splits up the SCC that the compiler manages into (potentially)
multiple ones after
performing lambda lifting. This aids both the closed term extractor and
the elimDeadBranches pass as
they are both negatively influenced when more declarations than required
are within one SCC.
This PR fixes the pretty-printing of the `extract_lets` tactic.
Previously, the pretty-printer would expect a space after the
`extract_lets` tactic, when it was followed by another tactic on the
same line: for example,
`extract_lets; exact foo`
would be changed to
`extract_lets ; exact foo`.
This PR fixes this oversight. Found by using the pretty-printer for
formatting linting in leanprover-community/mathlib4#30658.
This PR fixes an issue where go-to-definition would jump to the wrong
location in presence of async theorems.
While the elaborator does not explicitly depend on `FVar`s not being
reused between declarations, the language server turned out to do so. As
we would have to split the name generator in any case as soon as we add
any parallelism within proofs, we now do so for any async code in order
to uphold this invariant again.
---------
Co-authored-by: mhuisi <mhuisi@protonmail.com>
This PR adds support for simplifying the arguments of over-applied and
under-applied function application terms in `Sym.simp`, completing the
implementation for all three congruence strategies (fixed prefix,
interlaced, and congruence theorems).
This PR adds missing dependencies in `src/CMakeLists.txt` to ensure that
leanrt_initial-exec, leanrt, and leancpp_1 targets wait for copy-leancpp
to complete before building. Fixes potential build race conditions in
stage 2+ builds on systems with large `nproc`.
Closes https://github.com/leanprover/lean4/issues/11808
This PR removes the need to write `.ofNat` for numeric options in
`lakefile.lean`. Note that `lake translate-config` incorrectly assumed
this was already legal in earlier revisions.
This replaces #11771.
This PR implements support for auto-generated congruence theorems in
`Sym.simp`, enabling simplification of functions with complex argument
dependencies such as proof arguments and `Decidable` instances.
Previously, `Sym.simp` used basic congruence lemmas (`congrArg`,
`congrFun`, `congrFun'`, `congr`) to construct proofs when simplifying
function arguments. This approach is efficient for simple cases but
cannot handle functions with dependent proof arguments or `Decidable`
instances that depend on earlier arguments.
The new `congrThm` function applies pre-generated congruence theorems
(similar to the main simplifier) to handle these complex cases.
This PR fixes the `floatLetIn` pass to not move variables in case it
could break linearity (owned variables being passed with RC 1). This
mostly improves the situation in the parser which previously had many
functions that were supposed to be linear in terms of `ParserState` but
the compiler made them non-linear. For an example of how this affected
parsers:
```lean-4
def optionalFn (p : ParserFn) : ParserFn := fun c s =>
let iniSz := s.stackSize
let iniPos := s.pos
let s := p c s
let s := if s.hasError && s.pos == iniPos then s.restore iniSz iniPos else s
s.mkNode nullKind iniSz
```
previously moved the `let iniSz := ...` declaration into the `hasError`
branch. However, this means that at the point of calling the inner
parser (`p c s`), the original state `s` needs to have RC>1 because it
is used later in the `hasError` branch, breaking linearity. This fix
prevents such moves, keeping `iniSz` before the `p c s` call.
This PR introduces two induction principles for bitvectors, based on the
concat and cons operations. We show how this principle can be useful to
reason about bitvectors by refactoring two population count lemmas
(`cpopNatRec_zero_le` and `toNat_cpop_append`) and introducing a new
lemma (`toNat_cpop_not`).
To use the induction principle we also move `cpopNatRec_cons_of_le` and
`cpopNatRec_cons_of_lt` earlier in the popcount section (they are the
building blocks enabling us to take advantage of the new induction
principle).
---------
Co-authored-by: luisacicolini <luisacicolini@gmail.com>
Co-authored-by: Luisa Cicolini <48860705+luisacicolini@users.noreply.github.com>
This PR adds missing type checking for pattern variables during pattern
matching/unification to prevent incorrect matches.
Previously, the pattern matcher could incorrectly match expressions even
when pattern variable types were incompatible with the matched subterm
types. For example, a pattern like `x` where `x : BitVec 0` could match
any term, ignoring the specific type constraint on `x`.
This PR introduces a two-phase type checking approach:
1. **Static analysis** (`mkCheckTypeMask`): Identifies which pattern
variables require type checking based on their syntactic position.
Variables that appear only as arguments to function applications skip
checking (the application structure already constrains their types),
while variables in function position, binder contexts, or standalone
positions must be checked.
2. **Runtime validation**: During matching, when a pattern variable is
assigned, its type is checked against the matched subterm's type if
flagged by the mask. Checking uses `withReducible` to balance soundness
and performance.
The PR also adds helper functions for debugging (`Sym.mkMethods`,
`Sym.simpWith`, `Sym.simpGoal`) and fixes a minor issue where
`Theorem.rewrite` could return `.step` with identical expressions
instead of `.rfl`.Body:
This PR optimizes congruence proof construction in `Sym.simp` by
avoiding
`inferType` calls on expressions that are less likely to be cached.
Instead of
inferring types of expressions like `@HAdd.hAdd Nat Nat Nat instAdd 5`,
we infer
the type of the function prefix `@HAdd.hAdd Nat Nat Nat instAdd` and
traverse
the forall telescope.
The key insight is that function prefixes are more likely shared across
many call sites
(e.g., all `Nat` additions use the same `@HAdd.hAdd Nat Nat Nat
instAdd`), so they
benefit from `inferType` caching.
Benchmark results show improvements on workloads with shared function
prefixes:
- `many_rewrites_5000`: 48.8ms → 43.1ms (-12%)
- `term_tree_5000`: 53.4ms → 30.5ms (-43%)
This PR implements a new strategy for simplifying `have`-telescopes in
`Sym.simp` that achieves linear kernel type-checking time instead of
quadratic.
## Problem
When simplifying deep `have`-telescopes, the previous approach using
`have_congr'` produced proofs that type-checked in quadratic time. The
simplifier itself was fast, but the kernel became the bottleneck for
large telescopes.
For example, at n=100:
- **Before**: simp = 2.4ms, kernel = **225ms**
- **After**: simp = 3.5ms, kernel = **10ms**
The quadratic behavior occurred because the kernel creates fresh free
variables for each binder when type-checking, destroying sharing and
producing O(n²) intermediate terms.
## Solution
We transform sequential `have`-telescopes into a parallel
beta-application form:
```
have x₁ := v₁; have x₂ := v₂[x₁]; b[x₁, x₂]
↓ (definitionally equal)
(fun x₁ x₂' => b[x₁, x₂' x₁]) v₁ (fun x₁ => v₂[x₁])
```
This parallel form leverages the efficient simplifier for lambdas in
`Sym.simp`. This form enables:
1. Independent simplification of each argument
2. Proof construction using standard congruence lemmas
3. Linear kernel type-checking time
The algorithm has three phases:
1. **`toBetaApp`**: Transform telescope → parallel beta-application
2. **`simpBetaApp`**: Simplify using `congr`/`congrArg`/`congrFun'` and
`simpLambda`
3. **`toHave`**: Convert back to `have` form
## Benchmark Results
### Benchmark 1: Chain with all variables used in body
| n | Before (simp) | Before (kernel) | After (simp) | After (kernel) |
|---|---------------|-----------------|--------------|----------------|
| 50 | 1.2ms | 32ms | 1.6ms | 4.4ms |
| 100 | 2.4ms | **225ms** | 3.5ms | **10ms** |
| 200 | 4.5ms | — | 8.4ms | 27ms |
| 500 | 11.7ms | — | 33.6ms | 128ms |
### Benchmark 3: Parallel declarations (simplified values)
| n | Before (simp) | Before (kernel) | After (simp) | After (kernel) |
|---|---------------|-----------------|--------------|----------------|
| 50 | 0.5ms | 24ms | 0.8ms | 1.8ms |
| 100 | 1.2ms | **169ms** | 1.8ms | **5.3ms** |
| 200 | 2.2ms | — | 3.9ms | 17ms |
| 500 | 5.9ms | — | 12.3ms | 93ms |
### Benchmark 5: Chain with single dependency
| n | Before (simp) | Before (kernel) | After (simp) | After (kernel) |
|---|---------------|-----------------|--------------|----------------|
| 100 | 1.6ms | 6.2ms | 1.8ms | 6.2ms |
| 200 | 2.8ms | 21.6ms | 4.4ms | 16.5ms |
| 500 | 7.3ms | **125ms** | 12.8ms | **72ms** |
Key observations:
- Kernel time is now **linear** in telescope depth (previously
quadratic)
- Simp time increases slightly due to the transformation overhead
- Total time (simp + kernel) is dramatically reduced for large
telescopes
- The improvement is most pronounced when the body depends on many
variables
## Trade-offs
- Proof sizes are larger (more congruence lemma applications)
- Simp time has ~1.5x overhead from the transformation
- For very small telescopes (n < 10), the overhead may not pay off
The optimization targets the critical path: kernel type-checking was the
bottleneck preventing scaling to realistic symbolic simulation
workloads.
This PR fixes a panic that occurred when a theorem had a docstring on an
auxiliary definition within a `where` clause.
Reproducer:
```lean
theorem foo : True := aux where /-- -/ aux := True.intro
```
The issue was that `asyncMayModify` used `.any` to check if a nested
declaration could have its extension state modified, which returned
`false` when the declaration wasn't yet in `asyncConsts`. Using `.all`
instead returns `true` for `none` (vacuously true), allowing
modification
of extension state for nested declarations that haven't been added to
`asyncConsts` yet.
Closes#11799🤖 Prepared with Claude Code
---------
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
This PR fixes library suggestions to include private proof-valued
structure fields.
Private proof-valued structure fields (like `private size_keys' :
keys.size = values.size`) generate projections with `_private.*` mangled
names. These were being filtered out by `isDeniedPremise` because
`isInternalDetail` returns true for names starting with `_`.
The fix allows private names through by checking `!isPrivateName name`,
following the pattern from #11946. This enables `grind +suggestions` to
discover and use private proof-valued structure fields from the current
module.
Soon I would like to fix the semantics of `isInternalDetail`, as the
current behaviour is clearly wrong, but as there are many call sites, I
would like to get the behaviour of tactics correct first.
Also switches `currentFile` to use `wasOriginallyTheorem` instead of
matching on `.thmInfo`, which correctly identifies both theorems and
proof-valued projections.
🤖 Prepared with Claude Code
Co-authored-by: Claude <noreply@anthropic.com>
This PR adds guidance for investigating CI failures promptly rather than
waiting for other jobs to complete.
---
🤖 Prepared with Claude Code
Co-authored-by: Claude <noreply@anthropic.com>
This PR moves the `deriving instance BEq for Option` from
`Init.Data.Option.Basic` to `Init.Core`, making `BEq (Option α)`
available earlier in the import chain.
This is preparatory work for adding `maxSuggestions : Option Nat` fields
to `Grind.Config` and `Simp.Config`, which need `BEq (Option Nat)` for
the `deriving BEq` clause.
The duplicate derivation in `Init.Data.Option.Basic` is kept because
proofs there need the definition to be exposed.
🤖 Prepared with Claude Code
Co-authored-by: Claude <noreply@anthropic.com>
This PR adds a new `first_par` tactic combinator that runs multiple
tactics in parallel and returns the first successful result (cancelling
the others).
The `try?` tactic's `atomicSuggestions` step now uses `first_par` to try
three grind variants in parallel:
- `grind? +suggestions` - uses library suggestion engine
- `grind? +locals` - unfolds local definitions from current file
- `grind? +locals +suggestions` - combines both
This leverages `TacticM.parFirst` which already provides the "first
success wins" parallel execution with cancellation.
### Depends on
- [x] depends on: #11946🤖 Prepared with Claude Code
---------
Co-authored-by: Claude <noreply@anthropic.com>
This PR provides a `Decidable` instance for `Nat.isPowerOfTwo` based on
the formula `(n ≠ 0) ∧ (n &&& (n - 1)) = 0`.
To do this it includes theorems about `Nat.testBit` to show that the
`n.log2`th bit is set in `n` and `n - 1` for non powers of two.
Bitwise lemmas are needed to reason about the `&&&` so the file
`Init.Data.Nat.Power2` is renamed to `Init.Data.Nat.Power2.Basic` and
`Init.Data.Nat.Power2.Lemmas` introduced that depends on
`Init.Data.Nat.Bitwise.Lemmas` to prevent circular includes.
---------
Co-authored-by: Kim Morrison <477956+kim-em@users.noreply.github.com>
This PR changes the runtime implementation of the `Decidable (xs = #[])`
and `Decidable (#[] = xs)` instances to use `Array.isEmpty`. Previously,
`decide (xs = #[])` would first convert `xs` into a list and then
compare it against `List.nil`.
This PR adds a `+locals` configuration option to the `simp`, `simp_all`,
and `dsimp` tactics that automatically adds all definitions from the
current file to unfold.
Example usage:
```lean
def foo (n : Nat) : Nat := n + 1
-- Without +locals, simp doesn't know about foo
example (n : Nat) : foo n = n + 1 := by simp -- fails
-- With +locals, simp can unfold foo
example (n : Nat) : foo n = n + 1 := by simp +locals -- succeeds
```
The implementation iterates over `env.constants.map₂` (which contains
constants defined in the current module) and adds definitions to unfold.
Instance definitions and internal details are filtered out.
**Note:** For local theorems, use `+suggestions` instead, which will
include relevant local theorems via the library suggestion engine.
🤖 Prepared with [Claude Code](https://claude.com/claude-code)
Co-authored-by: Claude <noreply@anthropic.com>
This PR adds a `+locals` configuration option to the `grind` tactic that
automatically adds all definitions from the current file as e-match
theorems. This provides a convenient alternative to manually adding
`[local grind]` attributes to each definition. In the form `grind?
+locals`, it is also helpful for discovering which local declarations it
may be useful to add `[local grind]` attributes to.
Example usage:
```lean
def foo (n : Nat) : Nat := n + 1
-- Without +locals, grind doesn't know about foo
example (n : Nat) : foo n = n + 1 := by grind -- fails
-- With +locals, grind can use the equation
example (n : Nat) : foo n = n + 1 := by grind +locals -- succeeds
```
Instance definitions and internal details are filtered out.
🤖 Prepared with [Claude Code](https://claude.com/claude-code)
Co-authored-by: Claude <noreply@anthropic.com>
This PR makes the external checker lean4checker available as the
existing `leanchecker` binary already known to elan, allowing for
out-of-the-box access to it.
---------
Co-authored-by: Kim Morrison <kim@tqft.net>
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
This PR adds utility functions for managing the message log during
tactic
evaluation, and refactors existing code to use them.
**New helpers in `Lean.Elab.Tactic`:**
- `withSuppressedMessages`: executes an action while suppressing new
messages
- `withCapturedMessages`: executes an action and returns any new
messages
- `hasErrorMessages`: checks if a message list contains errors
**Refactored to use these helpers:**
- `LibrarySearch.tryDischarger`: now uses `withSuppressedMessages`
- `Try.evalAndSuggest`: now uses `withSuppressedMessages`
- `Try.evalAndSuggestWithBy`: now uses `withSuppressedMessages`
These helpers provide a standard pattern for tactic validation that
needs to
inspect error messages (e.g., filtering out suggestions that produce
errors).
🤖 Prepared with Claude Code
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
This PR ensures that pretty-printing of unification hints inserts a
space after |- resp. ⊢.
All uses in Lean core and mathlib add a space after the |- or ⊢ symbol;
this makes the output match usage in practice.
This was discovered in leanprover-community/mathlib4#30658, adding a
formatting linter using pretty-printing as initial guide.
This PR filters deprecated lemmas from `exact?` and `rw?` suggestions.
Previously, both tactics would suggest deprecated lemmas, which could be
confusing for users since using the suggestion would trigger a
deprecation warning.
Now, lemmas marked with `@[deprecated]` are filtered out in the
`addImport` functions that populate the discrimination trees used by
these tactics.
**Example (before this PR):**
```lean
import Mathlib.Logic.Basic
example (h : ∃ n : Nat, n > 0) : True := by
choose (n : Nat) (hn : n > 0 + 0) using h
guard_hyp hn : n > 0 -- `rw?` would suggest `Eq.rec_eq_cast` which is deprecated
```
Zulip discussion:
https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/deprecated.20lemma.20from.20rw.3F/near/554106870🤖 Prepared with Claude Code
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
This PR improves the error message when `initialize` (or `opaque`) fails
to find an `Inhabited` or `Nonempty` instance.
**Before:**
```
failed to synthesize
Inhabited Foo
```
**After:**
```
failed to synthesize 'Inhabited' or 'Nonempty' instance for
Foo
If this type is defined using the 'structure' or 'inductive' command, you can try adding a 'deriving Nonempty' clause to it.
```
Prompted by
https://leanprover.zulipchat.com/#narrow/channel/270676-lean4/topic/initialize.20structure.20with.20IO.2ERef/near/564936030🤖 Prepared with Claude Code
---------
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
This PR adds a symbol to the runtime for marking `Array`
non-linearities. This should allow users to
spot them more easily in profiles or hunt them down using a debugger.
This PR adds a new option to the function `simpHaveTelescope` in which
the `have` telescope is simplified in two passes:
* In the first pass, only the values and the body are simplified.
* In the second pass, unused declarations are eliminated.
This new mode eliminates **superlinear** behavior in the benchmark
`simp_3.lean`. Note that the kernel type checker still **exhibits**
quadratic behavior in this example, because it **does not have support**
for expanding a `have`/`let` telescope in a single step.
This PR adds two features to the message testing commands:
## `#guard_panic` command
A new `#guard_panic` command that succeeds if the nested command
produces a panic message. Unlike `#guard_msgs`, it does not check the
exact message content, only that a panic occurred.
This is useful for testing commands that are expected to panic, where
the exact panic message text may be volatile. It is particularly useful
when minimizing a panic discovered "in the wild", while ensuring the
panic behaviour is preserved.
## `substring := true` option for `#guard_msgs`
Adds a `substring := true` option to `#guard_msgs` that checks if the
docstring appears as a substring of the output (after whitespace
normalization), rather than requiring an exact match. This is useful
when you only care about part of the message.
Example:
```lean
/-- Unknown identifier -/
#guard_msgs (substring := true) in
example : α := x
```
## Refactoring
Also refactors `runAndCollectMessages` as a shared helper function used
by both `#guard_msgs` and `#guard_panic`.
🤖 Prepared with Claude Code
---------
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
This PR factors out the `have`-telescope support used in `simp`, and
implements it using the `MonadSimp` interface. The goal is to
use this nice infrastructure for both `Meta.simp` and `Sym.simp`.
This PR covers tactic docstrings in the documentation style guide.
At the Mathlib Initiative we want to ensure that tactics have good
documentation. Since this will involve adding documentation to tactics
built into core Lean, I discussed with David that we should write a
shared set of documentation guidelines that allow me to do my work both
on the Lean and on the Mathlib repositories.
I have already shown an earlier version of this guideline to David who
made some helpful suggestions but would be away for a few days. So to
make sure the discussion doesn't get lost, I've made a PR with the
version I ended up with after the first round of comments.
---------
Co-authored-by: Robert J. Simmons <442315+robsimmons@users.noreply.github.com>
This PR reorganizes the monad hierarchy for symbolic computation in
Lean.
## Motivation
We want a clean layering where:
1. A foundational monad (`SymM`) provides maximally shared terms and
structural/syntactic `isDefEq`
2. `GrindM` builds on this foundation, adding E-graphs, congruence
closure, and decision procedures
3. Symbolic execution / VCGen uses `GrindM` directly without introducing
a third monad
## Changes
The core symbolic computation layer still lives in `Lean.Meta.Sym`. This
monad (`SymM`) provides:
- Maximally shared terms with pointer-based equality
- Structural/syntactic `isDefEq` and matching (no reduction, predictable
cost)
- Monotonic local contexts (no `revert` or `clear`), enabling O(1)
metavariable validation
- Efficient `intro`, `apply`, and `simp` implementations
The name "Sym" reflects that this is infrastructure for symbolic
computation: symbolic simulation, verification condition generation, and
decision procedures.
### Updated hierarchy
```
Lean.Meta.Sym -- SymM: shared terms, syntactic isDefEq, intro, apply, simp
Lean.Meta.Grind -- GrindM: E-graphs, congruence closure (extends SymM)
```
Symbolic execution is a usage pattern of `GrindM` operating on
`Grind.Goal`, not a separate monad. This keeps the API surface minimal:
users learn two monads, and VCGen is "how you use `GrindM`" (for users
that want to use `grind`) rather than a third abstraction to understand.
This PR implements `PersistentHashMap.findKeyD` and
`PersistentHashSet.findD`. The motivation is avoid two memory
allocations (`Prod.mk` and `Option.some`) when the collections contains
the key.
This PR fixes an issue where `grind` failed to prove `f ≠ 0` from `f * r
≠ 0` when using `Lean.Grind.CommSemiring`, but succeeded with
`Lean.Grind.Semiring`.
The `propagateMul` propagator handles `0 * a = 0` and `a * 0 = 0` rules
for semirings that don't have full ring support in grind. Previously,
`CommSemiring` was excluded because it uses a ring envelope for
normalization, but that approach doesn't propagate these equalities back
to the original terms. Now `CommSemiring` also uses `propagateMul`.
Reported as
https://leanprover.zulipchat.com/#narrow/channel/270676-lean4/topic/Grind.20failure.20for.20CommSemiring.2C.20not.20Semiring🤖 Prepared with Claude Code
---------
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
This PR adds `gcd_left_comm` lemmas for both `Nat` and `Int`:
- `Nat.gcd_left_comm`: `gcd m (gcd n k) = gcd n (gcd m k)`
- `Int.gcd_left_comm`: `gcd a (gcd b c) = gcd b (gcd a c)`
These lemmas establish the left-commutativity property for gcd,
complementing the existing `gcd_comm` and `gcd_assoc` lemmas.
Upstreamed from
https://github.com/leanprover-community/mathlib4/pull/33235🤖 Prepared with Claude Code
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
This PR adds a `done` flag to the result returned by `Simproc`s in
`Sym.simp`.
The `done` flag controls whether simplification should continue after
the result:
- `done = false` (default): Continue with subsequent simplification
steps
- `done = true`: Stop processing, return this result as final
## Use cases for `done = true`
### In `pre` simprocs
Skip simplification of certain subterms entirely:
```
def skipLambdas : Simproc := fun e =>
if e.isLambda then return .rfl (done := true)
else return .rfl
```
### In `post` simprocs
Perform single-pass normalization without recursive simplification:
```
def singlePassNormalize : Simproc := fun e =>
if let some (e', h) ← tryNormalize e then
return .step e' h (done := true)
else return .rfl
```
With `done = true`, the result `e'` won't be recursively simplified.
This PR adds support for simplifying lambda expressions in `Sym.simp`.
It is much more efficient than standard simp for very large lambda
expressions with many binders. The key idea is to generate a custom
function extensionality theorem for the type of the lambda being
simplified.
This technique is compatible with the standard `simp` tactic, and will
be ported in a separate PR.
<img width="581" height="455" alt="image"
src="https://github.com/user-attachments/assets/5911dc6c-03f0-48ed-843b-b8cb4f67ee61"
/>
### `lambda` benchmark summary
| Lambda size | MetaM (ms) | SymM (ms) | Speedup |
|-------------|------------|-----------|---------|
| 50 | 22.7 | 0.74 | ~31× |
| 100 | 120.5 | 1.75 | ~69× |
| 150 | 359.6 | 2.90 | ~124× |
| 200 | 809.5 | 4.51 | ~180× |
This PR adds a guard to `TagDeclarationExtension.tag` to check if the
declaration name is anonymous and return early if so. This prevents a
panic that could occur when modifiers like `meta` or `noncomputable` are
used in combination with syntax errors.
Reproducer:
```lean
public meta section
def private
```
Previously this would panic with:
```
PANIC at Lean.EnvExtension.modifyState: called on `async` extension,
must set `asyncDecl` in that case
```
This follows the same pattern as the fix in #10131 for `addDocString`
and the existing guard in `markNotMeta`.
See
https://leanprover.zulipchat.com/#narrow/channel/270676-lean4/topic/panic.20on.20doc-string/near/566110399🤖 Prepared with Claude Code
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
This PR ensures that `Sym.simp` checks thresholds for maximum recursion
depth and maximum number of steps. It also invokes `checkSystem`.
Additionally, this PR simplifies the main loop. Assigned metavariables
and `zetaDelta` reduction are now handled by installing `pre`/`post`
methods.
This PR adds `getMatch` and `getMatchWithExtra` for retrieving patterns
from
discrimination trees in the symbolic simulation framework.
The PR also adds uses `DiscrTree` to implement indexing in `Sym.simp`.
This PR adds discrimination tree support for the symbolic simulation
framework.
The new `DiscrTree.lean` module converts `Pattern` values into
discrimination
tree keys, treating proof/instance arguments and pattern variables as
wildcards
(`Key.star`). Motivation: efficient pattern retrieval during rewriting.
This PR adds a `with_unfolding_none` tactic that sets the transparency
mode to `.none`, in which no definitions are unfolded. This complements
the existing `with_unfolding_all` tactic and provides tactic-level
access to the `TransparencyMode.none` added in
https://github.com/leanprover/lean4/pull/11810.
🤖 Prepared with Claude Code
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
This PR adds the directory `Meta/DiscrTree` and reorganizes the code
into different files. Motivation: we are going to have new functions for
retrieving simplification theorems for the new structural simplifier.
This PR improves the performance of `getLine` by coalescing the locking
of the underlying `FILE*`.
Unfortunately we cannot use `getline` or `fgets` for this as our code
needs to handle `\0` chars
and Windows.
This PR makes `mvcgen with tac` fail if `tac` fails on one of the VCs,
just as `induction ... with tac` fails if `tac` fails on one of the
goals. The old behavior can be recovered by writing `mvcgen with try
tac` instead.
This PR adds configuration flag `Meta.Context.cacheInferType`. You can
use it to disable the `inferType` cache at `MetaM`. We use this flag to
implement `SymM` because it has its own cache based on pointer equality.
This PR adds `CongrInfo` analysis for function applications in the
symbolic simulator framework. `CongrInfo` determines how to build
congruence proofs for rewriting subterms efficiently, categorizing
functions into:
- `none`: no arguments can be rewritten (e.g., proofs)
- `fixedPrefix`: common case where implicit/instance arguments form a
fixed prefix and explicit arguments can be rewritten (e.g., `HAdd.hAdd`,
`Eq`)
- `interlaced`: rewritable and non-rewritable arguments alternate (e.g.,
`HEq`)
- `congrTheorem`: uses auto-generated congruence theorems for functions
with dependent proof arguments (e.g., `Array.eraseIdx`)
This PR changes `bv_decide`'s heuristic for what kinds of structures to
split on to also allow
splitting on structures where the fields have dependently typed widths.
For example:
```lean
structure Byte (w : Nat) where
/-- A two's complement integer value of width `w`. -/
val : BitVec w
/-- A per-bit poison mask of width `w`. -/
poison : BitVec w
```
This is to allow handling situations such as `(x : Byte 8)` where the
width becomes concrete after
splitting is done.
This PR adds an incremental variant of `shareCommon` for expressions
constructed from already-shared subterms. We use this when an expression
`e` was produced by a Lean API (e.g., `inferType`, `mkApp4`) that does
not preserve maximal sharing, but the inputs to that API were already
maximally shared. Unlike `shareCommon`, this function does not use a
local `Std.HashMap ExprPtr Expr` to track visited nodes. This is more
efficient when the number of new (unshared) nodes is small, which is the
common case when wrapping API calls that build a few constructor nodes
around shared inputs.
This PR changes the definition of the iterator combinators `takeWhileM`
and `dropWhileM` so that they use `MonadAttach`. This is only relevant
in rare cases, but makes it sometimes possible to prove such combinators
finite when the finiteness depends on properties of the monadic
predicate.
This PR fixes a bug in the new pattern matching procedure for the Sym
framework. It was not correctly handling assigned metavariables during
pattern matching.
It also improves the support for free variables.
This PR adds performance comparison tests between the new `SymM` monad
and the standard `MetaM` for `intros`/`apply` operations.
The tests solve problems of the form:
```lean
let z := 0; ∀ x, ∃ y, x = z + y ∧ let z := z + x; ∀ x, ∃ y, x = z + y ∧ ... ∧ True
```
using repeated `intros` and `apply` with `Exists.intro`, `And.intro`,
`Eq.refl`, and `True.intro`.
**Results show 10-20x speedup:**
| Size | MetaM | SymM | Speedup |
|------|-------|------|---------|
| 1000 | 226ms | 21ms | 10.8x |
| 2000 | 582ms | 44ms | 13.2x |
| 3000 | 1.08s | 72ms | 15.0x |
| 4000 | 1.72s | 101ms | 17.0x |
| 5000 | 2.49s | 125ms | 19.9x |
| 6000 | 3.45s | 157ms | 22.0x |
This PR adds `BackwardRule` for efficient goal transformation via
backward chaining in `SymM`.
`BackwardRule` stores a theorem expression, precomputed pattern for
fast unification, and argument indices that become new subgoals. The
subgoal ordering lists non-dependent goals first to match the behavior
of `MetaM.apply`.
`BackwardRule.apply` unifies the goal type with the rule's pattern,
assigns the goal metavariable to the theorem application, and returns
new subgoals for unassigned arguments.
This PR makes the `FinitenessRelation` structure, which is helpful when
proving the finiteness of iterators, part of the public API. Previously,
it was marked internal and experimental.
This PR expands the pull request creation section with detailed
formatting guidelines including title format (type prefixes, imperative
present tense) and body format requirements (starting with "This PR").
Adds a concrete example for reference.
All modifications were suggested by Claude.
This PR adds `num?` parameter to `mkPatternFromTheorem` to control how
many leading quantifiers are stripped when creating a pattern. This
enables matching theorems where only some quantifiers should be
converted to pattern variables.
For example, to match `mk_forall_and : (∀ x, P x) → (∀ x, Q x) → (∀ x, P
x ∧ Q x)` against a goal `∀ x, q x 0 ∧ q (f (f x)) y`, we use
`mkPatternFromTheorem ``mk_forall_and (some 5)` to create the pattern `∀
x, ?P x ∧ ?Q x`, keeping the outermost `∀` in the pattern rather than
converting it to a pattern variable.
This PR completes the new pattern matching and unification procedures
for the symbolic simulation framework using a two-phase approach.
**Phase 1 (Syntactic Matching):**
- Patterns use de Bruijn indices for expression variables and renamed
level params for universe variables
- Purely structural matching after reducible definitions are unfolded
- Universe levels treat `max`/`imax` as uninterpreted functions
- Proof arguments skipped via proof irrelevance
- Instance and binder constraints deferred to Phase 2
**Phase 2 (Pending Constraints):**
- Level constraints: structural equality with mvar assignment
- Instance constraints: `isDefEqI` (full `isDefEq` for TC synthesis)
- Expression constraints: `isDefEqS` with Miller pattern support
- Unassigned instance pattern variables synthesized via
`trySynthInstance`
**`isDefEqS` (Structural DefEq):**
- Miller pattern detection and assignment (`?m x y z := rhs` → `?m :=
fun x y z => rhs`)
- Scope checking via `maxFVar` to prevent out-of-scope assignments
- Optional zeta-delta reduction for let-declarations
- Proof irrelevance and instance delegation to `isDefEqI`
**Key optimizations:**
- `abstractFVars` skips metavariables and uses `maxFVar` for early
cutoff
- Per-pattern `ProofInstInfo` cache for fast argument classification
- Maximal sharing.
This PR implements `isDefEqS`, a lightweight structural definitional
equality for the symbolic simulation framework. Unlike the full
`isDefEq`, it avoids expensive operations while still supporting Miller
pattern unification.
**Key features:**
- Structural matching with optional zeta-delta reduction for
let-declarations
- Miller pattern detection and assignment (`?m x y z := rhs` → `?m :=
fun x y z => rhs`)
- Scope checking via `maxFVar` to prevent out-of-scope assignments
- Proof arguments skipped via proof irrelevance
- Instance arguments delegated to full `isDefEq` (need TC machinery)
- Universe levels treated structurally (`max`/`imax` as uninterpreted)
This PR adds optimized `abstractFVars` and `abstractFVarsRange` for
converting free variables to de Bruijn indices during pattern
matching/unification.
**Optimizations:**
- Metavariables are skipped (their contexts must not include abstracted
fvars)
- Subterms whose `maxFVar` is below the minimal abstracted fvar are
skipped via early cutoff
- Results are maximally shared via `AlphaShareBuilderM`
These optimizations are sound for Miller pattern matching where
metavariables are created before entering binders.
This PR implements `instantiateRevBetaS`, which is similar to
`instantiateRevS` but beta-reduces nested applications whose function
becomes a lambda after substitution.
For example, if `e` contains a subterm `#0 a` and we apply the
substitution `#0 := fun x => x + 1`, then `instantiateRevBetaS` produces
`a + 1` instead of `(fun x => x + 1) a`.
This is useful when applying theorems. For example, when applying
`Exists.intro`:
```lean
Exists.intro.{u} {α : Sort u} {p : α → Prop} (w : α) (h : p w) : Exists p
```
to a goal of the form `∃ x : Nat, p x ∧ q x`, we create metavariables
`?w` and `?h`. With `instantiateRevBetaS`, the type of `?h` becomes `p
?w ∧ q ?w` instead of `(fun x => p x ∧ q x) ?w`.
This PR introduces a fast pattern matching and unification module for
the symbolic simulation framework (`Sym`). The design prioritizes
performance by using a two-phase approach:
**Phase 1 (Syntactic Matching)**
- Patterns use de Bruijn indices for expression variables and renamed
level params (`_uvar.0`, `_uvar.1`, ...) for universe variables
- Matching is purely structural after reducible definitions are unfolded
during preprocessing
- Universe levels treat `max` and `imax` as uninterpreted functions (no
AC reasoning)
- Binders and term metavariables are deferred to Phase 2
**Phase 2 (Pending Constraints)** [WIP]
- Handles binders (Miller patterns) and metavariable unification
- Converts remaining de Bruijn variables to metavariables
- Falls back to `isDefEq` when necessary
**Key design decisions:**
- Preprocessing unfolds reducible definitions and performs beta/zeta
reduction
- Kernel projections are expected to be folded as projection
applications before matching
- Assignment conflicts are deferred to pending rather than invoking
`isDefEq` inline
- `instantiateRevS` ensures maximal sharing of result expressions
**TODO:**
- Skip instance arguments during matching, synthesize later
- Skip proof arguments (proof irrelevance)
- Implement `processPending` for Phase 2 constraints
This PR refactors the `Goal` type used in `grind`. The new
representation allows multiple goals with different metavariables to
share the same `GoalState`. This is useful for automation such as
symbolic simulator, where applying theorems create multiple goals that
inherit the same E-graph, congruence closure and solvers state, and
other accumulated facts.
This PR implements `intro` (and its variants) for `SymM`. These versions
do not use reduction or infer types, and ensure expressions are
maximally shared.
This PR adds the function `Sym.instantiateS` and its variants, which are
similar to `Expr.instantiate` but assumes the input is maximally shared
and ensures the output is also maximally shared.
This PR adds the function `Sym.replaceS`, which is similar to
`replace_fn` available in the kernel but assumes the input is maximally
shared and ensures the output is also maximally shared. The PR also
generalizes the `AlphaShareBuilder` API.
This PR simplifies `AlphaShareCommon.State` by separating the persistent
and transient parts of the state.
The `map` field caches visited sub-expressions during a single
`shareCommonAlpha` call to handle DAGs efficiently, the input expression
may contain shared sub-expressions that are not yet maximally shared.
However, this cache does not need to persist between different
`shareCommonAlpha` calls.
**Changes:**
- Moved `map` from the persistent `AlphaShareCommon.State` to a private
`State` used only within individual `shareCommonAlpha` calls.
- Replaced `PHashMap ExprPtr Expr` with (the more efficient)
`Std.HashMap ExprPtr Expr` for `map`, since it is now local to each call
and does not need persistence.
- The public `AlphaShareCommon.State` now only contains the `set` of
alpha-equivalent expressions that should persist
This PR adds functions for creating maximally shared terms from
maximally shared terms. It is more efficient than creating an expression
and then invoking `shareCommon`. We are going to use these functions for
implementing the symbolic simulation primitives.
This PR introduces `SymM`, a new monad for implementing symbolic
simulators (e.g., verification condition generators) in Lean. The monad
addresses performance issues found in symbolic simulators built on top
of user-facing tactics like `apply` and `intros`.
**Key features:**
- Goals are represented by `Grind.Goal` objects, enabling incremental
hypothesis processing
- No `revert` or `clear` operations, allowing O(1) local context checks
instead of O(n log n)
- Carries `GrindM` state across goals to avoid reprocessing shared
hypotheses
- Provides `mkGoal` for creating new goals within the monad
This is the foundational infrastructure for `SymM`. Future PRs will add
operations like `intro`, `apply`, and the optimized definitional
equality test.
This PR adds support for incrementally processing local declarations in
`grind`. Instead of processing all hypotheses at once during goal
initialization, `grind` now tracks which local declarations have been
processed via `Goal.nextDeclIdx` and provides APIs to process new
hypotheses incrementally.
This feature will be used by the new `SymM` monad for efficient symbolic
simulation.
This PR disables closed term extraction in the reflection terms used by
`bv_decide`. These terms do
not profit at all from closed term extraction but can in practice cause
thousands of new closed term
declarations which in turn slows down the compiler.
This PR improves the performance of and flattening in `bv_decide`.
The two main insights of this PR are:
1. When embedded constraint substitution is disabled it makes no sense
to have and flattening on in
the first place, given that we do not profit from it in any way.
2. The new fvars produced by and flattening can also be inserted into
the rewriting caches of the
preprocessing pipeline if the fvar they were derived from is already in
the cache. This
drastically decreases the amount of work we have to do in the second
rewriting pass after running
and flattening.
This PR adds the attributes `[grind norm]` and `[grind unfold]` for
controlling the `grind` normalizer/preprocessor.
The `norm` modifier instructs `grind` to use a theorem as a
normalization rule. That is, the theorem is applied during the
preprocessing step. This feature is meant for advanced users who
understand how the preprocessor and `grind`'s search procedure interact
with each other.
New users can still benefit from this feature by restricting its use to
theorems that completely eliminate a symbol from the goal. Example:
```lean
theorem max_def : max n m = if n ≤ m then m else n
```
For a negative example, consider:
```lean
opaque f : Int → Int → Int → Int
theorem fax1 : f x 0 1 = 1 := sorry
theorem fax2 : f 1 x 1 = 1 := sorry
attribute [grind norm] fax1
attribute [grind =] fax2
example (h : c = 1) : f c 0 c = 1 := by
grind -- fails
```
In this example, `fax1` is a normalization rule, but it is not
applicable to the input goal since `f c 0 c` is not an instance of `f x
0 1`. However, `f c 0 c` matches the pattern `f 1 x 1` modulo the
equality `c = 1`. Thus, `grind` instantiates `fax2` with `x := 0`,
producing the equality `f 1 0 1 = 1`, which the normalizer simplifies to
`True`. As a result, nothing useful is learned. In the future, we plan
to include linters to automatically detect issues like these. Example:
```lean
opaque f : Nat → Nat
opaque g : Nat → Nat
@[grind norm] axiom fax : f x = x + 2
@[grind norm ←] axiom fg : f x = g x
example : f x ≥ 2 := by grind
example : f x ≥ g x := by grind
example : f x + g x ≥ 4 := by grind
```
The `unfold` modifier instructs `grind` to unfold the given definition
during the preprocessing step. Example:
```lean
@[grind unfold] def h (x : Nat) := 2 * x
example : 6 ∣ 3*h x := by grind
```
This PR fixes a mismatch between the behavior of `foldlM` and
`foldlMUnsafe` in the three array
types. This mismatch is only exposed when manually specifying a `stop`
value greater than the size
of the array and only exploitable through `native_decide`.
The mismatch was introduced as part of
4ba21ea10c which introduced
`foldlMUnsafe` and thus likely a mistake when building the `unsafe`
implementation instead of a
specification mistake.
Closes#11773
This PR implements support for user-defined attributes at
`grind_pattern`. Suppose we have declared the `grind` attribute
```lean
register_grind_attr my_grind
```
Then, we can now write
```lean
opaque f : Nat → Nat
opaque g : Nat → Nat
axiom fg : g (f x) = x
grind_pattern [my_grind] fg => g (f x)
```
This PR uses the new support for user-defined `grind` attributes to
implement the default `[grind]` attribute.
A manual update-stage0 is required because it affects the .olean files.
This PR implements user-defined `grind` attributes. They are useful for
users that want to implement tactics using the `grind` infrastructure
(e.g., `progress*` in Aeneas). New `grind` attributes are declared using
the command
```lean
register_grind_attr my_grind
```
The command is similar to `register_simp_attr`. After the new attribute
is declared. Recall that similar to `register_simp_attr`, the new
attribute cannot be used in the same file it is declared.
```lean
opaque f : Nat → Nat
opaque g : Nat → Nat
@[my_grind] theorem fax : f (f x) = f x := sorry
example theorem fax2 : f (f (f x)) = f x := by
fail_if_success grind
grind [my_grind]
```
TODO: remove leftovers after update stage0
This PR allows `grind` to use `List.eq_nil_of_length_eq_zero` (and
`Array.eq_empty_of_size_eq_zero`), but only when it has already proved
the length is zero.
This PR moves the grind pattern from `Sublist.eq_of_length` to the
slightly more general `Sublist.eq_of_length_le`, and adds a grind
pattern guard so it only activates if we have a proof of the hypothesis.
This PR adds additional test coverage for #11758 (fix for #11745:
nonstandard instances in grind and simp +arith).
The existing test `grind_11745.lean` only covers Int LE with `grind
-order` and `lia -order`. This adds tests for:
- LT instances (Int and Nat)
- Nat LE instances
- Mixed canonical and non-canonical instances in the same goal
- Equality derived from two LE constraints
- `simp +arith` with non-canonical instances
🤖 Prepared with Claude Code
Co-authored-by: Claude <noreply@anthropic.com>
This PR adds a Python script that helps find which commit introduced a
behavior change in Lean. It supports multiple bisection modes and
automatically downloads CI artifacts when available.
- [x] depends on: #11735
## Usage
```
usage: lean-bisect [-h] [--timeout SEC] [--ignore-messages] [--verbose]
[--selftest] [--clear-cache] [--nightly-only]
[file] [RANGE]
Bisect Lean toolchain versions to find where behavior changes.
positional arguments:
file Lean file to test (must only import Lean.* or Std.*)
RANGE Range to bisect: FROM..TO, FROM, or ..TO
options:
-h, --help show this help message and exit
--timeout SEC Timeout in seconds for each test run
--ignore-messages Compare only exit codes, ignore stdout/stderr differences
--verbose, -v Show stdout/stderr from each test
--selftest Run built-in selftest to verify lean-bisect works
--clear-cache Clear CI artifact cache (~600MB per commit) and exit
--nightly-only Stop after finding nightly range (don't bisect individual
commits)
Range Syntax:
FROM..TO Bisect between FROM and TO
FROM Start from FROM, bisect to latest nightly
..TO Bisect to TO, search backwards for regression start
If no range given, searches backwards from latest nightly to find regression.
Identifier Formats:
nightly-YYYY-MM-DD Nightly build date (e.g., nightly-2024-06-15)
Uses pre-built toolchains from leanprover/lean4-nightly.
Fast: downloads via elan (~30s each).
v4.X.Y or v4.X.Y-rcN Version tag (e.g., v4.8.0, v4.9.0-rc1)
Converts to equivalent nightly range.
Commit SHA Git commit hash (short or full, e.g., abc123def)
Bisects individual commits between two points.
Tries CI artifacts first (~30s), falls back to building (~2-5min).
Commits with failed CI builds are automatically skipped.
Artifacts cached in ~/.cache/lean-bisect/artifacts/
Bisection Modes:
Nightly mode: Both endpoints are nightly dates.
Binary search through nightlies to find the day behavior changed.
Then automatically continues to bisect individual commits.
Use --nightly-only to stop after finding the nightly range.
Version mode: Either endpoint is a version tag.
Converts to equivalent nightly range and bisects.
Commit mode: Both endpoints are commit SHAs.
Binary search through individual commits on master.
Output: "Behavior change introduced in commit abc123"
Examples:
# Simplest: just provide the file, finds the regression automatically
lean-bisect test.lean
# Specify an endpoint if you know roughly when it broke
lean-bisect test.lean ..nightly-2024-06-01
# Full manual control over the range
lean-bisect test.lean nightly-2024-01-01..nightly-2024-06-01
# Only find the nightly range, don't continue to commit bisection
lean-bisect test.lean nightly-2024-01-01..nightly-2024-06-01 --nightly-only
# Add a timeout (kills slow/hanging tests)
lean-bisect test.lean --timeout 30
# Bisect commits directly (if you already know the commit range)
lean-bisect test.lean abc1234..def5678
# Only compare exit codes, ignore output differences
lean-bisect test.lean --ignore-messages
# Clear downloaded CI artifacts to free disk space
lean-bisect --clear-cache
```
🤖 Prepared with Claude Code
---------
Co-authored-by: Claude <noreply@anthropic.com>
This PR fixes an issue where `grind` fails when trying to unfold a
definition by pattern matching imported by `import all` (or from a
non-`module`).
Fixes#11715
---------
Co-authored-by: Sebastian Ullrich <sebasti@nullri.ch>
This PR turns even more commonly used bv_decide theorems that require
unification into fast simprocs
using syntactic equality. This pushes the overall performance across
sage/app7 to <= 1min10s for
every problem.
This PR replaces `ffi.md` with links to the corresponding sections of
the manual, so we don't have to keep two documents up to date.
A corresponding reference manual PR re-synchronizes them:
https://github.com/leanprover/reference-manual/pull/714
This PR upstreams dependency-management commands from Mathlib:
- `#import_path Foo` prints the transitive import chain that brings
`Foo` into scope
- `assert_not_exists Foo` errors if declaration `Foo` exists (for
dependency management)
- `assert_not_imported Module` warns if `Module` is transitively
imported
- `#check_assertions` verifies all pending assertions are eventually
satisfied
These commands help maintain the independence of different parts of a
library by catching unintended transitive dependencies early.
### Example usage
```lean
-- Find out how Nat got into scope
#import_path Nat
-- Declaration Nat is imported via
-- Init.Prelude,
-- which is imported by Init.Coe,
-- which is imported by Init.Notation,
-- ...
-- which is imported by this file.
-- Assert that a declaration should not be in scope yet
assert_not_exists SomeAdvancedType
-- Assert that a module should not be imported
assert_not_imported Some.Heavy.Module
-- Verify all assertions are eventually satisfied
#check_assertions
```
Addresses
https://lean-fro.zulipchat.com/#narrow/channel/398861-general/topic/path.20of.20an.20import🤖 Prepared with Claude Code
---------
Co-authored-by: Claude <noreply@anthropic.com>
This PR adds a standalone script to download pre-built CI artifacts from
GitHub Actions. This allows us to quickly switch commits without
rebuilding.
**Features:**
- Downloads artifacts for current HEAD or specified commit (`--sha`)
- Caches in `~/.cache/lean_build_artifact/` for reuse
- Platform detection (Linux/macOS, x86_64/aarch64)
**Usage:**
```
build_artifact.py # Download for current HEAD
build_artifact.py --sha abc1234 # Download for specific commit
build_artifact.py --clear-cache # Clear cache
```
This is extracted to be shared with `lean-bisect`.
🤖 Prepared with Claude Code
Co-authored-by: Claude <noreply@anthropic.com>
This PR fixes an issue where `exact?` would not suggest private
declarations defined in the current module.
## Problem
When using `exact?` in a file with private declarations, those private
declarations were not being suggested even though they are valid and
accessible:
```lean
module
axiom P : Prop
private axiom p : P
example : P := by exact? -- error: could not find lemma
```
The problem was that `blacklistInsertion` in `LazyDiscrTree` was
filtering out all declarations whose names matched `isInternalDetail`,
which includes private names due to their `_private.Module.0.name`
structure.
## Solution
The fix adds a helper function `isPrivateNameOf` that checks if a
private declaration belongs to a specific module. The
`blacklistInsertion` function now allows private declarations belonging
to the current module (`env.header.mainModule`) to pass through the
filter.
Private declarations from imported modules are still filtered out, as
they may reference internal declarations that aren't accessible (which
would cause processing errors).
Zulip discussion:
https://leanprover.zulipchat.com/#narrow/channel/270676-lean4/topic/.60exact.3F.60.20and.20private.20declarations/near/564586152🤖 Prepared with Claude Code
---------
Co-authored-by: Claude <noreply@anthropic.com>
This PR introduces some additional lemmas around `BitVec.extractLsb'`
and `BitVec.extractLsb`.
---------
Co-authored-by: Tobias Grosser <github@grosser.es>
Co-authored-by: Tobias Grosser <tobias@grosser.es>
This PR internalizes all arguments of Quot.lift during LCNF conversion,
preventing panics in certain
non trivial programs that use quotients.
Fixes#11719.
This PR improves the performance of the functions for generating
congruence lemmas, used by `simp`
and a few other components.
It is a followup to (though not dependent on) #11717 and improves the
performance of `bv_decide` on the benchmark
in question further down to 20 seconds (from 1min 23s in #11717 and 8min
originally). We are thus at approximately a 24x speedup from the
original run.
This PR improves the performance of `bv_decide`'s rewriter on large
problems.
The baseline for this PR is `QF_BV/sage/app7/bench_1222.smt2` on
`chonk3` at 8 minutes. After this
PR it takes about 1min and 23 seconds. This improvement is achieved by
turning frequently used simp
rules into simprocs in order to avoid spending time performing
unification to see if they are
applicable.
This PR renames the namespace `Std.Range` to `Std.Legacy.Range`. Instead
of using `Std.Range` and `[a:b]` notation, the new range type `Std.Rco`
and its corresponding `a...b` notation should be used. There are also
other ranges with open/closed/infinite boundary shapes in
`Std.Data.Range.Polymorphic` and the new range notation also works for
`Int`, `Int8`, `UInt8`, `Fin` etc.
This PR adds more MPL spec lemmas for all combinations of `for` loops,
`fold(M)` and the `filter(M)/filterMap(M)/map(M)` iterator combinators.
These kinds of loops over these combinators (e.g. `it.mapM`) are first
transformed into loops over their base iterators (`it`), and if the base
iterator is of type `Iter _` or `IterM Id _`, then another spec lemma
exists for proving Hoare triples about it using an invariant and the
underlying list (`it.toList`). The PR also fixes a bug that MPL always
assigns the default priority to spec lemmas if `Std.Tactic.Do.Syntax` is
not imported and a bug that low-priority lemmas are preferred about
high-priority ones.
For context, the MPL bug was related to the fact that the `Attr.spec`
syntax is not built-in. Therefore, Lean falls back to the `Attr.simple`
syntax, which *basically* also works, but which stores the priority at a
different position. The routine to extract the priority does not
consider this and so it falls back to the default priority given an
`Attr.simple` syntax object.
This PR improves the performance of autocompletion and fuzzy matching by
introducing an ASCII fast path into one of their core loops and making
Char.toLower/toUpper more efficient.
Co-authored-by: Rob23oba <152706811+Rob23oba@users.noreply.github.com>
This PR gives a focused error message when a user tries to name an
example, and tweaks error messages for attempts to define multiple
opaque names at once.
## Example errors
```
example x : 1 == 1 := by grind
```
Current message:
```
Failed to infer type of binder `x`
Note: Because this declaration's type has been explicitly provided, all parameter types and holes (e.g., `_`) in its header are resolved before its body is processed; information from the declaration body cannot be used to infer what these values should be
```
New message:
```
Failed to infer type of binder `x`
Note: Examples don't have names. The identifier `x` is being interpreted as a parameter `(x : _)`.
```
## Plural-aware identifier lists
Both the example errors and opaque errors understand pluralization and
use oxford commas.
```
opaque a b c : Nat
```
Current message:
```
Failed to infer type of binder `c`
Note: Multiple constants cannot be declared in a single declaration. The identifier(s) `b`, `c` are being interpreted as parameters `(b : _)`, `(c : _)`.
```
New message:
```
Failed to infer type of binder `c`
Note: Multiple constants cannot be declared in a single declaration. The identifiers `b` and `c` are being interpreted as parameters `(b : _)` and `(c : _)`.```
This PR extends the get-elem tactic for ranges so that it supports
subarrays. Example:
```lean
example {a : Array Nat} (h : a.size = 28) : Id Unit := do
let mut x := 0
for h : i in *...(3 : Nat) do
x := a[1...4][i]
```
This PR avoids invoking TC synthesis and other inference mechanisms in
the simprocs of bv_decide. This can give significant speedups on
problems that pressure these simprocs.
This PR enables the specializer to also recursively specialize in some
non trivial higher order situations.
The main motivation for this change is the upcoming changes to do
notation by sgraf. In there he uses combinators such as
```lean
@[specialize, expose]
def List.newForIn {α β γ} (l : List α) (b : β) (kcons : α → (β → γ) → β → γ) (knil : β → γ) : γ :=
match l with
| [] => knil b
| a :: l => kcons a (l.newForIn · kcons knil) b
```
in programs such as
```lean
def testing :=
let x := 42;
List.newForIn (β := Nat) (γ := Id Nat)
[1,2,3]
x
(fun i kcontinue s =>
let x := s;
List.newForIn
[i:10].toList x
(fun j kcontinue s =>
let x := s;
let x := x + i + j;
kcontinue x)
kcontinue)
pure
```
inspecting this IR right before we get to the specializer in the current
compiler we get:
```
[Compiler.eagerLambdaLifting] size: 22
def testing : Nat :=
fun _f.1 _y.2 : Nat :=
return _y.2;
let x := 42;
let _x.3 := 1;
fun _f.4 i kcontinue s : Nat :=
fun _f.5 j kcontinue s : Nat :=
let _x.6 := Nat.add s i;
let x := Nat.add _x.6 j;
let _x.7 := kcontinue x;
return _x.7;
let _x.8 := 10;
let _x.9 := Nat.sub _x.8 i;
let _x.10 := Nat.add _x.9 _x.3;
let _x.11 := 1;
let _x.12 := Nat.sub _x.10 _x.11;
let _x.13 := Nat.mul _x.3 _x.12;
let _x.14 := Nat.add i _x.13;
let _x.15 := @List.nil _;
let _x.16 := List.range'TR.go _x.3 _x.12 _x.14 _x.15;
let _x.17 := @List.newForIn _ _ _ _x.16 s _f.5 kcontinue;
return _x.17;
let _x.18 := 2;
let _x.19 := 3;
let _x.20 := @List.nil _;
let _x.21 := @List.cons _ _x.19 _x.20;
let _x.22 := @List.cons _ _x.18 _x.21;
let _x.23 := @List.cons _ _x.3 _x.22;
let _x.24 := @List.newForIn _ _ _ _x.23 x _f.4 _f.1;
return _x.24
```
Here the `kcontinue` higher order functions pose a special challenge
because they delay the discovery of new specialization opportunities.
Inspecting the IR after the current specializer (and a cleanup simp
step) we get functions that look as follows:
```
[simp] size: 7
def List.newForIn._at_.testing.spec_0 i kcontinue l b : Nat :=
cases l : Nat
| List.nil =>
let _x.1 := kcontinue b;
return _x.1
| List.cons head.2 tail.3 =>
let _x.4 := Nat.add b i;
let x := Nat.add _x.4 head.2;
let _x.5 := List.newForIn._at_.testing.spec_0 i kcontinue tail.3 x;
return _x.5
[simp] size: 14
def List.newForIn._at_.List.newForIn._at_.testing.spec_1.spec_1 _x.1 l b : Nat :=
cases l : Nat
| List.nil =>
return b
| List.cons head.2 tail.3 =>
fun _f.4 x.5 : Nat :=
let _x.6 := List.newForIn._at_.List.newForIn._at_.testing.spec_1.spec_1 _x.1 tail.3 x.5;
return _x.6;
let _x.7 := 10;
let _x.8 := Nat.sub _x.7 head.2;
let _x.9 := Nat.add _x.8 _x.1;
let _x.10 := 1;
let _x.11 := Nat.sub _x.9 _x.10;
let _x.12 := Nat.mul _x.1 _x.11;
let _x.13 := Nat.add head.2 _x.12;
let _x.14 := @List.nil _;
let _x.15 := List.range'TR.go _x.1 _x.11 _x.13 _x.14;
let _x.16 := List.newForIn._at_.testing.spec_0 head.2 _f.4 _x.15 b;
return _x.16
```
Observe that the specializer decided to abstract over `kcontinue`
instead of specializing further recursively. Thus this tight loop is now
going through an indirect call.
This PR now changes the specializer somewhat fundamentally to handle
situations like this. The most notable change is going to a fixpoint
loop of:
1. Specialize all current declarations in the worklist
2. If a declaration
- succeeded in specializing run the simplifier on it and put it back
onto the worklist
- if it didn't don't put it back onto the worklist anymore
3. Put all newly generated specialisations on the worklist
4. Recompute fixed parameters for the current SCC
5. Repeat until the worklist is empty
Furthermore, declarations that were already specialized:
- only consider `fixedHO` parameters for specialization, in order to
avoid termination issues with repeated specialization and abstraction of
type class parameters under binders
- recursively specialized declarations only allow specialization if at
least one of their fixedHO arguments is not a parameter itself. The
reason for allowing this in first generation specialization is that we
refrain from specializing inside the body of a declaration marked as
`@[specialize]`. Thus we need to specialize them even if their arguments
don't actually contain anything of interest in order to ensure that type
classes etc. are correctly cleaned up within their bodies.
There is one last trade-off to consider. When specializing code
generated by the new do elaborator we sometimes generate intermediate
specializations that are not actually part of any call graph after we
are done specializing. We could in principle detect these functions and
delete them but having them in cache is potentially helpful for further
specializations later. Once the new do elaborator lands we plan to test
this trade-off.
Closes#10924
This PR provides many lemmas about `Int` ranges, in analogy to those
about `Nat` ranges. A few necessary basic `Int` lemmas are added. The PR
also removes `simp` annotations on `Rcc.toList_eq_toList_rco`,
`Nat.toList_rcc_eq_toList_rco` and consorts.
This PR adds the definition of `BitVec.cpop`, which relies on the more
general `BitVec.cpopNatRec`, and build some theory around it. The name
`cpop` aligns with the [RISCV ISA
nomenclature](https://msyksphinz-self.github.io/riscv-isadoc/#_cpop).
Co-authored-by: @tobiasgrosser, @bollu
---------
Co-authored-by: Tobias Grosser <tobias@grosser.es>
Co-authored-by: Tobias Grosser <github@grosser.es>
Co-authored-by: Siddharth <siddu.druid@gmail.com>
This PR makes it possible to verify loops over iterators. It provides
MPL spec lemmas about `for` loops over pure iterators. It also provides
spec lemmas that rewrite loops over `mapM`, `filterMapM` or `filterM`
iterator combinators into loops over their base iterator.
This PR refactors match compilation, to handle “side-effect free”
patterns (`.var`, `.inaccessible`, `.as`) eagerly and for each
alternative separately. The idea is that there should be less interplay
between different alternatives, and prepares the ground for #11105.
This may cause some corner case match statements to compiler or fail
compile that behaved differently before. For example, it can now use a
sparse case where previously was using a full case, and pattern
completeness may not be clear to lean now. On the other hand, using a
sparse case can mean that match statements mixing matching in indicies
with matching on the indexed datatype can work.
This PR removes the unnecessary check for the batteries
`nightly-testing-YYYY-MM-DD` tag that blocks mathlib CI from running.
## Problem
Currently, when fixing mathlib's nightly-testing branch, the workflow
requires BOTH batteries and mathlib to have `nightly-testing-YYYY-MM-DD`
tags before mathlib CI can run on lean4 PRs. This creates a false
dependency:
1. Fix mathlib nightly-testing (including fixing batteries build)
2. Mathlib CI succeeds → creates mathlib tag → advances
`nightly-with-mathlib`
3. But batteries test suite fails → no batteries tag created
4. lean4 PR can't run mathlib CI because batteries tag doesn't exist
5. Bot suggests rebasing onto `nightly-with-mathlib`, but this doesn't
help
## Solution
Remove the batteries tag check because:
- Mathlib CI already depends on batteries (builds it as a dependency)
- If batteries is broken, mathlib CI will detect it
- The batteries testing branch creation already has fallback logic
(falls back to `nightly-testing` branch if tag doesn't exist)
This allows mathlib CI to run as soon as mathlib is ready, which is the
actual blocker.
See discussion at
https://leanprover.zulipchat.com/#narrow/channel/428973-nightly-testing/topic/Mathlib.20status.20updates/near/564136025🤖 Prepared with Claude Code
Co-authored-by: Claude Sonnet 4.5 <noreply@anthropic.com>
This PR fixes `grind` to support dot notation on declarations in the
lemma list.
When using `grind only [foo.le]` where `foo.le` is dot notation applying
`LT.lt.le` to a theorem `foo`, grind previously failed with "Unknown
constant `foo.le`" because it tried to look up `foo.le` as a constant
name rather than elaborating it as a term.
The fix adds a fallback in `processParam`: when constant lookup fails,
it now falls back to `processTermParam` which elaborates the identifier
as a term. This allows dot notation expressions like `log_two_lt_d9.le`
to work correctly.
Closes#11690🤖 Prepared with Claude Code
---------
Co-authored-by: Claude <noreply@anthropic.com>
This PR adds the following repositories to the release configuration:
- lean4-unicode-basic
- BibtexQuery (depends on lean4-unicode-basic)
- verso-web-components (depends on verso)
It also updates dependencies:
- doc-gen4 now depends on BibtexQuery
- lean-fro.org now depends on verso-web-components
🤖 Prepared with Claude Code
This PR adds the new operation `MonadAttach.attach` that attaches a
proof that a postcondition holds to the return value of a monadic
operation. Most non-CPS monads in the standard library support this
operation in a nontrivial way. The PR also changes the `filterMapM`,
`mapM` and `flatMapM` combinators so that they attach postconditions to
the user-provided monadic functions passed to them. This makes it
possible to prove termination for some of these for which it wasn't
possible before. Additionally, the PR adds many missing lemmas about
`filterMap(M)` and `map(M)` that were needed in the course of this PR.
This PR improves `match` generalization such that it abstracts
metavariables in types of local variables and in the result type of the
match over the match discriminants. Previously, a metavariable in the
result type would silently default to the behavior of `generalizing :=
false`, and a metavariable in the type of a free variable would lead to
an error (#8099). Example of a `match` that elaborates now but
previously wouldn't:
```lean
example (a : Nat) (ha : a = 37) :=
(match a with | 42 => by contradiction | n => n) = 37
```
This is because the result type of the `match` is a metavariable that
was not abstracted over `a` and hence generalization failed; the result
is that `contradiction` cannot pick up the proof `ha : 42 = 37`.
The old behavior can be recovered by passing `(generalizing := false)`
to the `match`.
Furthermore, programs such as the following can now be elaborated:
```lean
example (n : Nat) : Id (Fin (n + 1)) :=
have jp : ?m := ?rhs
match n with
| 0 => ?jmp1
| n + 1 => ?jmp2
where finally
case m => exact Fin (n + 1) → Id (Fin (n + 1))
case jmp1 => exact jp ⟨0, by decide⟩
case jmp2 => exact jp ⟨n, by omega⟩
case rhs => exact pure
```
This is useful for the `do` elaborator.
Fixes#8099.
This PR makes `simpH`, used in the match equation generator, produce a
proof term. This is in preparation for a bigger refactoring in #11512.
This removes some cases, these are no longer necessary since #11196.
This PR fixes an inconsistency in the way Lake and Lean view the
transitivity of a `meta import`. Lake now works as Lean expects and
includes the meta segment of all transitive imports of a `meta import`
in its transitive trace.
This PR adds the `Context` type for cancellation with context
propagation. It works by storing a tree of forks of the main context,
providing a way to control cancellation.
This PR changes the "declaration uses 'sorry'" warning to use backticks
instead of single quotes, consistent with Lean's conventions for
formatting code identifiers in diagnostic messages.
Fix a typo in the error message when an unknown role is used in a
docstring.
- Changes "Unkown role" to "Unknown role" in
`src/Lean/Elab/DocString.lean`
This PR fixes the `grind` support for `Nat.ctorIdx`. Nat constructors
appear in `grind` as offsets or literals, and not as a node marked
`.constr`, so handle that case as well.
This PR moves many constants of the iterator API from `Std.Iterators` to
the `Std` namespace in order to make them more convenient to use. These
constants include, but are not limited to, `Iter`, `IterM` and
`IteratorLoop`. This is a breaking change. If something breaks, try
adding `open Std` in order to make these constants available again. If
some constants in the `Std.Iterators` namespace cannot be found, they
can be found directly in `Std` now.
This PR adds a CI step that fails if the `src/stdlib_flags.h` file was
modified, to alert PR authors that they most likely wanted to modify
`stage0/src/stdlib_flags.h` instead.
This PR adds basic support for equality propagation in `grind linarith`
for the `IntModule` case. This covers only the basic case. See note in
the code.
We remark this feature is irrelevant for `CommRing` since `grind ring`
already has much better support for equality propagation.
This PR fixes an issue where a `by` in the public scope could create an
auxiliary theorem for the proof whose type does not match the expected
type in the public scope.
Fixes#11672
This PR adds support for `Nat.cast` in `grind linarith`. It now uses
`Grind.OrderedRing.natCast_nonneg`. Example:
```lean
open Lean Grind Std
attribute [instance] Semiring.natCast
variable [Lean.Grind.CommRing R] [LE R] [LT R] [LawfulOrderLT R] [IsLinearOrder R] [OrderedRing R]
example (a : Nat) : 0 ≤ (a : R) := by grind
example (a b : Nat) : 0 ≤ (a : R) + (b : R) := by grind
example (a : Nat) : 0 ≤ 2 * (a : R) := by grind
example (a : Nat) : 0 ≥ -3 * (a : R) := by grind
```
This PR fixes the `grind` pattern validator. It covers the case where an
instance is not tagged with the implicit instance binder. This happens
in declarations such as
```lean
ZeroMemClass.zero_mem {S : Type} {M : outParam Type} {inst1 : Zero M} {inst2 : SetLike S M}
[self : @ZeroMemClass S M inst1 inst2] (s : S) : 0 ∈ s
```
This PR adds explicit guidance to the `/release` command that Claude
should never merge PRs autonomously during the release process - always
wait for the user to do it.
🤖 Prepared with Claude Code
This PR updates the release checklist script. The cslib repository no
longer has a docs subdirectory, so the release script was failing when
trying to update lakefile.toml and lean-toolchain in that nonexistent
directory.
This PR adds support for `Int.sign`, `Int.fdiv`, `Int.tdiv`, `Int.fmod`,
`Int.tmod`, and `Int.bmod` to `grind`. These operations are just
preprocessed away. We assume that they are not very common in practice.
Examples:
```lean
example {x y : Int} : y = 0 → (x.fdiv y) = 0 := by grind
example {x y : Int} : y = 0 → (x.tdiv y) = 0 := by grind
example {x y : Int} : y = 0 → (x.fmod y) = x := by grind
example {x y : Int} : y = 1 → (x.fdiv (2 - y)) = x := by grind
example {x : Int} : x > 0 → x.sign = 1 := by grind
example {x : Int} : x < 0 → x.sign = -1 := by grind
example {x y : Int} : x.sign = 0 → x*y = 0 := by grind
```
See #11622
This PR adds propagation rules corresponding to the `Semiring`
normalization rules introduced in #11628. The new rules apply only to
non-commutative semirings, since support for them in `grind` is limited.
The normalization rules introduced unexpected behavior in Mathlib
because they neutralize parameters such as `one_mul`: any theorem
instance associated with such a parameter is reduced to `True` by the
normalizer.
This PR teaches `grind` how to reduce `.ctorIdx` applied to
constructors. It can also handle tasks like
```
xs ≍ Vec.cons x xs' → xs.ctorIdx = 1
```
thanks to a `.ctorIdx.hinj` theorem (generated on demand).
This PR fixes a SIGFPE crash on x86_64 when evaluating `INT_MIN / -1` or
`INT_MIN % -1` for signed integer types.
On x86_64, the `idiv` instruction traps when the quotient overflows the
destination register. For signed integers, `INT_MIN / -1` produces a
result that overflows (e.g., `-2147483648 / -1 = 2147483648` which
doesn't fit in Int32). ARM64's `sdiv` instruction wraps instead of
trapping.
The fix:
- For Int8/Int16/Int32: widen to the next larger type before
dividing/modding, then truncate back
- For Int64: explicitly check for the overflow case and return the
wrapped result
Fixes#11612🤖 Prepared with Claude Code
This PR fixes a typo in the docstring of `LeanLibConfig.defaultFacets`
and the Lake README that erroneously referred to `LeanLib.sharedLib`
instead of `LeanLib.sharedFacet`.
See e.g. `tests/lake/tests/targets/lakefile.lean` to verify that
`LeanLib.sharedFacet` is correct usage; `LeanLib.sharedLib` does not
exist.
This PR adds support for `BitVec.ofNat` in `grind lia`. Example:
```lean
example (x y : BitVec 8) : y < 254#8 → x > 2#8 + y → x > 1#8 + y := by
grind
```
This PR implements a linter that warns when a deprecated coercion is
applied. It also warns when the `Option` coercion or the
`Subarray`-to-`Array` coercion is used in `Init` or `Std`. The linter is
currently limited to `Coe` instances; `CoeFun` instances etc. are not
considered.
The linter works by collecting the `Coe` instance declaration names that
are being expanded in `expandCoe?` and storing them in the info tree.
The linter itself then analyzes the info tree and checks for banned or
deprecated coercions.
This PR ensures the pattern normalizer used in `grind` does violate
assumptions made by the gadgets `Grind.genPattern` and
`Grind.getHEqPattern`.
Closes#11633
This PR adjusts the new `meta` keyword of the experimental module system
not to imply `partial` for general consistency.
As the previous behavior can create confusion return types that are not
known to be `Nonempty` and few `def`s should be `meta` in the first
case, this special case does not appear to be worth the minor
convenience.
This PR adds BEq instance for `DTreeMap`/`TreeMap`/`TreeSet` and their
extensional variants and proves lemmas relating it to the equivalence of
hashmaps/equality of extensional variants.
Stacked on top of #11266
This PR adds `@[suggest_for ℤ]` on `Int` and `@[suggest_for ℚ]` on
`Rat`, following the pattern established by `@[suggest_for ℕ]` on `Nat`
in #11554.
🤖 Prepared with Claude Code
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
This PR causes Lean to search through `@[suggest_for]` annotations on
certain errors that look like unknown identifiers that got incorrectly
autobound. This will correctly identify that a declaration of type
`Maybe String` should be `Option String` instead.
## Example
```
example : Except String Unit := return .ok ()
```
```
Function expected at
Result
but this term has type
?m.1
Note: Expected a function because this term is being applied to the argument
String
Hint: The identifier `Result` is unknown, and Lean's `autoImplicit` option causes an unknown identifier to be treated as an implicitly bound variable with an unknown type. However, the unknown type cannot be a function, and a function is what Lean expects here. This is often the result of a typo or a missing `import` or `open` statement.
Perhaps you meant `Except` in place of `Result`?
```
The last line is added by this PR.
This PR allows Lean to present suggestions based on `@[suggest_for]`
annotations for unknown identifiers without internal dots. (The
annotations in #11554 only gave suggestion for dotted identifiers like
`Array.every`->`Array.all` and not for bare identifiers like
`Result`->`Except` or `ℕ`->`Nat`.)
This PR makes argument-less tactic invokations of `Std.Do` tactics such
as `mintro` emit a proper error message "`mintro` expects at least one
pattern" instead of claiming that `Std.Tactic.Do` needs to be imported.
Closes#11509.
This PR ensures we apply the ring normalizer to equalities being
propagated from the `grind` core module to `grind lia`. It also ensures
we use the safe/managed polynomial functions when normalizing.
Closes#11539
This PR improves the case-split heuristics in `grind`. In this PR, we do
not increment the number of case splits in the first case. The idea is
to leverage non-chronological backtracking: if the first case is solved
using a proof that doesn't depend on the case hypothesis, we backtrack
and close the original goal directly. In this scenario, the case-split
was "free", it didn't contribute to the proof. By not counting it, we
allow deeper exploration when case-splits turn out to be irrelevant.
The new heuristic addresses the second example in #11545
This PR removes the old ElimDeadBranches pass and shifts the new one
past lambda lifting.
The reason for dropping the old one is its general unsoundness and the
fact that we want to do refactorings on the IR part. The reason for
shifting the current pass past lambda lifting, is that its analysis is
imprecise in the presence of local function symbols. I experimented with
the exact placement for a while and it seems like it is optimal here.
Overall we observe a slight regression in the amount of C code
generated, likely because we don't propagate information into lambdas
before lifting them anymore. But generally measure a slight performance
improvement in general.
This PR fixes how theorems without parameters are handled in `grind`.
This is a better fix than #11579
---------
Co-authored-by: Kim Morrison <kim@tqft.net>
This PR moves Lake's `tests/lake/examples/targets` test from `examples`
to `tests` (and thus disabling it by default).
It is being
[flaky](https://github.com/leanprover/lean4/actions/runs/20111185289/attempts/1)
for some unknown reason, so I am disabling until I have a better
opportunity to debug it.
This PR ensures that ground theorems are properly handled as `grind`
parameters. Additionally, `grind [(thm)]` and `grind [thm]` should be
handled the same way.
---------
Co-authored-by: Kim Morrison <kim@tqft.net>
This PR fixes `grind?` to include term parameters (like `[show P by
tac]`) in its suggestions. Previously, these were being dropped because
term arguments are stored in `extraFacts` and not tracked via E-matching
like named lemmas.
For example, `grind? [show False by exact h]` now correctly suggests
`grind only [show False by exact h]` instead of just `grind only`.
🤖 Prepared with Claude Code
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
This PR adds a `+all` option to `exact?` and `apply?` that collects all
successful lemmas instead of stopping at the first complete solution.
When `+all` is enabled:
- `exact?` shows all lemmas that completely solve the goal (admits the
goal with `sorry`)
- `apply?` shows all lemmas including both complete and partial
solutions
🤖 Prepared with Claude Code
<!-- CURSOR_SUMMARY -->
---
> [!NOTE]
> Adds a +all flag to exact? and apply? to collect all successful
lemmas, updates library search to support aggregation and proper
star-lemma fallback, and extends the discriminator tree to
extract/append dropped entries; includes tests.
>
> - **Tactics / UI**:
> - Add `LibrarySearchConfig.all` and `+all` flag to `exact?`/`apply?`
to collect all successful lemmas.
> - `exact?` now aggregates complete solutions (via
`addExactSuggestions`); `apply?` shows both complete and partial
suggestions.
> - Updated help texts and error/hint messages.
> - **Library Search Core (`Lean.Meta.Tactic.LibrarySearch`)**:
> - Thread new `collectAll` option through `tryOnEach`,
`librarySearch'`, and `librarySearch`.
> - `tryOnEach` continues collecting complete solutions when `collectAll
= true`.
> - Star-lemma fallback now runs even when primary search yields only
partial results; include complete solutions when aggregating.
> - Cache and retrieve star-indexed lemmas via
`droppedEntriesRef`/`getStarLemmas`.
> - **Lazy Discriminator Tree (`Lean.Meta.LazyDiscrTree`)**:
> - Add `extractKey(s)`/`collectSubtreeAux` to extract and drop entries,
returning them.
> - Modify import/module tree building to optionally append dropped
entries to a shared ref (for star-lemmas), and pass this through
`findMatches`/`createModuleTreeRef`.
> - Minor comment/logic tweaks (append vs set) when handling dropped
entries.
> - **Elaboration (`Lean.Elab.Tactic.LibrarySearch`)**:
> - Integrate `collectAll` into `exact?`/`apply?`; partition and present
complete vs incomplete suggestions; admit goals appropriately when
aggregating.
> - **Tests**:
> - Update existing expectations and add
`tests/lean/run/library_search_all.lean` to verify `+all`, aggregation,
and star-lemma behavior.
>
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
cbfc9313af. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->
---------
Co-authored-by: Claude <noreply@anthropic.com>
This PR documents that tests in `tests/lean/run/` run with
`-Dlinter.all=false`, and explains how to enable specific linters when
testing linter behavior.
🤖 Prepared with Claude Code
This PR fixes `grind` rejecting dot notation terms, mistaking them for
local hypotheses.
When a grind parameter like `n.triv` is given, where `n` is a local
variable and `triv` is a theorem that takes `n` as an argument (so
`n.triv` means `Nat.triv n`), grind was incorrectly rejecting it with
"redundant parameter" because it detected that the identifier resolved
to a local variable via `resolveLocalName`.
The fix checks if `resolveLocalName` returns field projections
(non-empty list), indicating dot notation. In that case, we process the
parameter as a term expression to let elaboration resolve the dot
notation properly, rather than trying to resolve it as a global constant
name.
### Minimal reproducer
```lean
theorem Nat.triv (n : Nat) : n = n := rfl
example (n : Nat) : n = n := by
grind [n.triv] -- Previously: "redundant parameter `n.triv`"
```
This also fixes the issue where `grind [x.exp_pos]` was rejected even
though `x.exp_pos` elaborates to `Real.exp_pos x`, a valid theorem
application.
🤖 Prepared with Claude Code
This PR adds missing lemmas about how `ReaderT.run`, `OptionT.run`,
`StateT.run`, and `ExceptT.run` interact with `MonadControl` operations.
This also leaves some comments noting that the lemmas may look less
general than expected; but this is because the instances are also not
very general.
This PR fixes an issue where `grind` did not display deprecation
warnings when deprecated lemmas were used in its argument list.
The fix adds explicit calls to `Linter.checkDeprecated` after resolving
theorem names in both `processParam` (for theorem arguments) and
`elabGrindParams` (for the `-` erase syntax).
Closes#11582🤖 Prepared with Claude Code
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
This PR adds a lemma that the cast of a natural number into any ordered
ring is non-negative. We can't annotate this directly for `grind`, but
will probably add this to `grind`'s linarith interrnals.
This PR adds `@[suggest_for]` annotations to Lean, allowing lean to
provide corrections for `.every` or `.some` methods in place of `.all`
or `.any` methods for most default-imported types (arrays, lists,
strings, substrings, and subarrays, and vectors).
Due to the need for stage0 updates for new annotations, the
`suggest_for` annotation itself was introduced in previous PRs: #11367,
#11529, and #11590.
## Example
```
example := "abc".every (! ·.isWhitespace)
```
Error message:
```
Invalid field `every`: The environment does not contain `String.every`, so it is not possible to project the field `every` from an expression
"abc"
of type `String`
Hint: Perhaps you meant `String.all` in place of `String.every`:
.e̵v̵e̵r̵y̵a̲l̲l̲
```
(the hint is added by this PR)
## Additional changes
Adds suggestions that are not currently active but that can be used to
generate autocompletion suggestions in the reference manual:
- `Either` -> `Except` and `Sum`
- `Exception` -> `Except`
- `ℕ` -> `Nat`
- `Nullable` -> `Option`
- `Maybe` -> `Option`
- `Optional` -> `Option`
- `Result` -> `Except`
This PR switches the way olean files store identifier suggestions. The
ordering introduced in #11367 and #11529 made sense if we were only
storing incorrect -> correct mappings, but for the reference manual we
want to store the correct -> incorrect mappings as well, and so it is
more sensible to store just the correct -> incorrect mapping that mimics
the author-generated data better.
Also tweaks error messages further in preparation for public-facing
@[suggest_for] annotations and forbids suggestions on non-public names.
Does not make generally-visible changes as there are no introduced uses
of @[suggest_for] annotations yet.
These complement the existing `ExceptT.mk` and `OptionT.mk`, and provide
a symbol to key `simp` lemmas on, to prevent getting stuck on
`StateT.run (fun s => f s) s`.
A future PR could insert these new `mk`s into the implementation of many
definitions, such that unfolding the definitions leaves appropriate
casts behind; but this is invasive, and by itself having `mk` provides
value.
This PR improves indexing for `grind` patterns. We now include symbols
occurring in nested ground patterns. This important to minimize the
number of activated E-match theorems.
This PR makes the noConfusion principles even more heterogeneous, by
allowing not just indices but also parameters to be differ.
This is a breaking change for manual use of `noConfusion` for types with
parameters. Pass suitable `rfl` arguments, and use `eq_of_heq` on the
resulting equalities as needed.
This fixes#11560.
This PR adds `BEq` instance for `DHashMap`/`HashMap`/`HashSet` and their
extensional variants and proves lemmas relating it to the equivalence of
hashmaps/equality of extensional variants.
This PR allows projections on `tagged` values in the IR type system.
While executing this branch of code should indeed never happen in
practice, enforcing this through
the type system would require the compiler to always optimize code to
the point where this is not
possible. For example in the code:
```
cases x with
| none => ....
| some =>
let val : obj := proj[0] x
...
```
static analysis might learn that `x` is always none and transform this
to:
```
let x : tagged := none
cases x with
| none => ....
| some =>
let val : obj := proj[0] x
...
```
Which would be type incorrect if projections on `tagged` were
illegitimate. However, we don't want
to force static analysis to always simplify code far enough on its own
to enforce this invariant.
This PR prevents `try` swallowing heartbeat errors from nested `simp`
calls, and more generally ensures the `isRuntime` flag is propagated by
`throwNestedTacticEx`. This prevents the behavior of proofs (especially
those using `aesop`) being affected by the current recursion depth or
heartbeat limit.
This breaks a single caller in Mathlib where `simp` uses a lemma of the
form `x = f (g x)` and stack overflows, which can be fixed by
generalizing over `g x`.
Closes#7811.
---------
Co-authored-by: Sebastian Ullrich <sebasti@nullri.ch>
This PR fixes the tactic framework reporting file progress bar ranges
that cover up progress inside tactic blocks nested in tactic
combinators. This is a purely visual change, incremental re-elaboration
inside supported combinators was not affected.
Also adds a test though it is not elaborate enough to test proper timing
of progress events per se; see moddoc there.
This PR scans the environment for viable replacements for a dotted
identifier (like `.zero`) and suggests concrete alternatives as
replacements.
## Example
```
#example .zero
```
Error message:
```
Invalid dotted identifier notation: The expected type of `.cons` could not be determined
```
Additional hint added by this PR:
```
Hint: Using one of these would be unambiguous:
[apply] `BitVec.cons`
[apply] `List.cons`
[apply] `List.Lex.cons`
[apply] `List.Pairwise.cons`
[apply] `List.Perm.cons`
[apply] `List.Sublist.cons`
[apply] `List.Lex.below.cons`
[apply] `List.Pairwise.below.cons`
[apply] `List.Perm.below.cons`
[apply] `List.Sublist.below.cons`
[apply] `Lean.Grind.AC.Seq.cons`
```
## Additional changes
This PR also brings several related error message descriptions and code
actions more in line with each other, changing several "Suggested
replacement: " code actions to the more common "Change to " wording, and
sorts suggestions obtained from searching the context by the default
sort for Names (which prefers names with fewer segments).
This PR adds some information to Grove: a check that all
string/slice-transforming functions are tracked properly (which finds
dozens of missed cases), and some documentation of design designs around
naming in the string library.
The PR also bumps the Grove version to the latest version which contains
many new features and also processes the data a lot faster (40s to 2.5s
for the test project).
This PR ensures that `Nat`s in `.olean` files use a deterministic
serialization in the case where `LEAN_USE_GMP` is not set.
This is a simplified version of
https://github.com/leanprover/lean4/pull/2908.
This PR reviews the docstrings for `Std.Do` that will appear in the Lean
reference manual and adds those that were missing.
---------
Co-authored-by: Sebastian Graf <sgraf1337@gmail.com>
This PR adds a workspace-index to the name of the package used by build
target. To clarify the distinction between the different uses of a
package's name, this PR also deprecates `Package.name` for more
use-specific variants (e.g., `Package.keyName`, `Package.prettyName`,
`Package.origName`).
More to come. (WIP)
This PR introduces a new fixpoint combinator,
`WellFounded.extrinsicFix`. A termination proof, if provided at all, can
be given extrinsically, i.e., looking at the term from the outside, and
is only required if one intends to formally verify the behavior of the
fixpoint. The new combinator is then applied to the iterator API.
Consumers such as `toList` or `ForIn` no longer require a proof that the
underlying iterator is finite. If one wants to ensure the termination of
them intrinsically, there are strictly terminating variants available
as, for example, `it.ensureTermination.toList` instead of `it.toList`.
This PR introduces the new `tagged_return` attribute. It allows users to
mark `extern` declarations to be guaranteed to always return `tagged`
return values. Unlike with `object` or `tobject` the compiler does not
emit reference counting operations for them. In the future information
from this attribute will be used for a more powerful analysis to remove
reference counts when possible.
This PR ensures the auxiliary definitions created by
`register_try?_tactic` are internal implementation details that should
not be visible to user-facing linters.
🤖 Generated with Claude Code
This PR adds support for underscores as digit separators in
String.toNat?, String.toInt?, and related parsing functions. This makes
the string parsing functions consistent with Lean's numeric literal
syntax, which already supports underscores for readability (e.g.,
100_000_000).
The implementation validates that underscores:
- Cannot appear at the start or end of the number
- Cannot appear consecutively
- Are ignored when calculating the numeric value
This resolves a common source of friction when parsing user input from
command-line arguments, environment variables, or configuration files,
where users naturally expect to use the same numeric syntax they use in
source code.
## Examples
Before:
```lean
#eval "100_000_000".toNat? -- none
```
After:
```lean
#eval "100_000_000".toNat? -- some 100000000
#eval "1_000".toInt? -- some 1000
#eval "-1_000_000".toInt? -- some (-1000000)
```
## Testing
Added comprehensive tests in
`tests/lean/run/string_toNat_underscores.lean` covering:
- Basic underscore support
- Edge cases (leading/trailing/consecutive underscores)
- Both `toNat?` and `toInt?` functions
- String, Slice, and Substring types
All existing tests continue to pass.
Closes#11538🤖 Prepared with Claude Code
---------
Co-authored-by: Claude Sonnet 4.5 <noreply@anthropic.com>
This PR makes it so that in the issue template a line about how to check
boxes is in comment form you can only see it when you are creating the
issue and it does not need to be displayed to everyone.
Hi, these are just some spelling corrections.
There is one I wasn't completely sure about in
src/Init/Data/List/Lemmas.lean:
> See also
> ...
> Also
> \* \`Init.Data.List.Monadic\` for **addiation** _(additional?)_ lemmas
about \`List.mapM\` and \`List.forM\`
This PR fixes a syntax-pattern-matching issue from #11367 that prevented
the addition of suggestions in Init prior to Lean.Parser being
introduced, which was a significant shortcoming. It preserves the
ability to have multiple suggestions for one annotation later in the
process.
Additionally, tweaks a (not-yet-user-visible) error message and modifies
the attribute declaration to store a wrongIdentifier ->
correctIdentifier mapping instead of a correctIdentifier ->
wrongIdentifier mapping.
This PR makes the LCNF simplifier eliminate cases where all alts are
`.unreach` to just an `.unreach`.
an `.unreach`
We considered dropping a cases in a situation like this but decided
against it because it might hinder reuse.
```
def test x : Bool :=
cases x : Bool
| Except.error a.1 =>
⊥
| Except.ok a.2 =>
let _x.3 := true;
return _x.3
```
This PR avoids generating hyps when not needed (i.e. if there is a
catch-all so no completeness checking needed) during matching on values.
This tweak was made possible by #11220.
This PR adds a difference operation on
`ExtDTreeMap`/`ExtTreeMap`/`TreeSet` and proves several lemmas about it.
Stacked on top of #11407
---------
Co-authored-by: Markus Himmel <markus@himmel-villmar.de>
This PR implements new flags and annotations for `shake` for use in
Mathlib:
> Options:
> --keep-implied
> Preserves existing imports that are implied by other imports and thus
not technically needed
> anymore
>
> --keep-prefix
> If an import `X` would be replaced in favor of a more specific import
`X.Y...` it implies,
> preserves the original import instead. More generally, prefers
inserting `import X` even if it
> was not part of the original imports as long as it was in the original
transitive import closure
> of the current module.
>
> --keep-public
> Preserves all `public` imports to avoid breaking changes for external
downstream modules
>
> --add-public
> Adds new imports as `public` if they have been in the original public
closure of that module.
> In other words, public imports will not be removed from a module
unless they are unused even
> in the private scope, and those that are removed will be re-added as
`public` in downstream
> modules even if only needed in the private scope there. Unlike
`--keep-public`, this may
> introduce breaking changes but will still limit the number of inserted
imports.
>
> Annotations:
> The following annotations can be added to Lean files in order to
configure the behavior of
> `shake`. Only the substring `shake: ` directly followed by a directive
is checked for, so multiple
> directives can be mixed in one line such as `-- shake:
keep-downstream, shake: keep-all`, and they
> can be surrounded by arbitrary comments such as `-- shake: keep
(metaprogram output dependency)`.
>
> * `module -- shake: keep-downstream`:
> Preserves this module in all (current) downstream modules, adding new
imports of it if needed.
>
> * `module -- shake: keep-all`:
> Preserves all existing imports in this module as is. New imports now
needed because of upstream
> changes may still be added.
>
> * `import X -- shake: keep`:
> Preserves this specific import in the current module. The most common
use case is to preserve a
> public import that will be needed in downstream modules to make sense
of the output of a
> metaprogram defined in this module. For example, if a tactic is
defined that may synthesize a
> reference to a theorem when run, there is no way for `shake` to detect
this by itself and the
> module of that theorem should be publicly imported and annotated with
`keep` in the tactic's
> module.
> ```
> public import X -- shake: keep (metaprogram output dependency)
>
> ...
>
> elab \"my_tactic\" : tactic => do
> ... mkConst ``f -- `f`, defined in `X`, may appear in the output of
this tactic
> ```
This PR implements `grind` propagators for `Nat` operators that have a
simproc associated with them, but do not have any theory solver support.
Examples:
```lean
example (a b : Nat) : a = 3 → b = 6 → a &&& b = 2 := by grind
example (a b : Nat) : a = 3 → b = 6 → a ||| b = 7 := by grind
example (a b : Nat) : a = 3 → b = 6 → a ^^^ b = 5 := by grind
example (a b : Nat) : a = 3 → b = 6 → a <<< b = 192 := by grind
example (a b : Nat) : a = 1135 → b = 6 → a >>> b = 17 := by grind
```
Closes#11498
This PR marks `Nat` power and divisibility theorems for `grind`. We use
the new `grind_pattern` constraints to control theorem instantiation.
Examples:
```lean
example {x m n : Nat} (h : x = 4 ^ (m + 1) * n) : x % 4 = 0 := by
grind
example (a m n o p : Nat) : a ∣ n → a ∣ m * n * o * p := by
grind
example {a b x m n : Nat}
: n > 0 → x = b * 4^m * a → a = 9^n → m > 0 → x % 6 = 0 := by
grind
example {a n : Nat}
: m > 4 → a = 2^(m^n) → a % 2 = 0 := by
grind
```
Closes#11515
Remark: We are adding support for installing extra theorems to `lia`
(aka `cutsat`). The example at #11515 can already be solved by `grind`
with this PR, but we still need to add the new theorems to the set for
`lia`.
cc @kim-em
This PR provides an additional hint when the type of an autobound
implicit is required to have function type or equality type — this
fails, and the existing error message does not address the fact that the
source of the error is an unknown identifier that was automatically
bound.
## Example
```
import Lean
example : MetaM String := pure ""
```
Current error message:
```
Function expected at
MetaM
but this term has type
?m
Note: Expected a function because this term is being applied to the argument
String
```
Additional error message provided by this PR:
```
Hint: The identifier `MetaM` is unknown, and Lean's `autoImplicit` option
causes an unknown identifier to be treated as an implicitly bound variable
with an unknown type. However, the unknown type cannot be a function, and a
function is what Lean expects here. This is often the result of a typo or a
missing `import` or `open` statement.
```
This PR re-enables star-indexed lemmas as a fallback for `exact?` and
`apply?`.
Star-indexed lemmas (those with overly-general discrimination tree keys
like `[*]`)
were previously dropped entirely for performance reasons. This caused
useful lemmas
like `Empty.elim`, `And.left`, `not_not.mp`, `Sum.elim`, and
`Function.mtr` to be
unfindable by library search.
The implementation adds a two-pass search strategy:
1. First, search using concrete discrimination keys (the current
behavior)
2. If no results are found, fall back to trying star-indexed lemmas
The star-indexed lemmas are extracted during tree initialization and
cached in an
environment extension, avoiding repeated computation.
Users can disable the fallback with `-star`:
```lean
example {α : Sort u} (h : Empty) : α := by apply? -star -- error: no lemmas found
example {α : Sort u} (h : Empty) : α := by apply? -- finds Empty.elim
```
🤖 Prepared with Claude Code
---------
Co-authored-by: Claude <noreply@anthropic.com>
This PR adds support for the difference operation for
`ExtDHashMap`/`ExtHashMap`/`ExtHashSet` and proves several lemmas about
it.
---------
Co-authored-by: Markus Himmel <markus@himmel-villmar.de>
This PR changes how match splitters are generated: Rather than rewriting
the match statement, the match compilation pipeline is used again.
The benefits are:
* Re-doing the match compilation means we can do more intelligent book
keeping, e.g. prove overlap assumptions only once and re-use the proof,
or prune the context of the MVar to speed up `contradiction`. This may
have allowed a different solution than #11200.
* It would unblock #11105, as the existing splitter implementation would
have trouble dealing with the matchers produced that way.
* It provides the necessary machinery also for source-exposed “none of
the above” bindings, a feature that we probably want at some point (and
we mostly need to find good syntax for, see #3136, although maybe I
should open a dedicated RFC).
* It allows us to skip costly things during matcher creation that would
only be useful for the splitter, and thus allows performance
improvements like #11508.
* We can drop the existing implementation.
It’s not entirely free:
* We have to run `simpH` twice, once for the match equations and once
for the splitter.
This PR introduces a new annotation that allows definitions to describe
plausible-but-wrong name variants for the purpose of improving error
messages.
This PR just adds the notation and extra functionality; a stage0 update
will allow standard Lean functions to have suggestion annotations.
(Hence the changelog-no tag: this should go in the changelog when some
preliminary annotations are actually added.)
## Example
```lean4
inductive MyBool where | tt | ff
attribute [suggest_for MyBool.true] MyBool.tt
attribute [suggest_for MyBool.false] MyBool.ff
@[suggest_for MyBool.not]
def MyBool.swap : MyBool → MyBool
| tt => ff
| ff => tt
/--
error: Unknown constant `MyBool.true`
Hint: Perhaps you meant `MyBool.tt` in place of `MyBool.true`:
M̵y̵B̵o̵o̵l̵.̵t̵r̵u̵e̵M̲y̲B̲o̲o̲l̲.̲t̲t̲
-/
#guard_msgs in
example := MyBool.true
/--
error: Invalid field `not`: The environment does not contain `MyBool.not`, so it is not possible to project the field `not` from an expression
MyBool.tt
of type `MyBool`
Hint: Perhaps you meant one of these in place of `MyBool.not`:
[apply] `MyBool.swap`: MyBool.tt.swap
-/
#guard_msgs in
example := MyBool.tt.not
```
This PR marks `Char -> Bool` patterns as default instances for string
search. This means that things like `" ".find (·.isWhitespace)` can now
be elaborated without error.
Previously, it was necessary to write `" ".find Char.isWhitespace`.
Thank you to David Christiansen for the idea of using a default
instance.
This PR gives suggestions based on the currently-available constants
when projecting from an unknown type.
## Example: single suggestion in namespace
This was the originally motivating example, as the string refactor led
to a number of anonymous-lambda-expressions with `Char` functions that
were no longer recognized as such.
```lean4
example := (·.isWhitespace)
```
Before:
```
Invalid field notation: Type of
x✝
is not known; cannot resolve field `isWhitespace`
```
The message is unchanged, but this PR adds a hint:
```
Hint: Consider replacing the field projection `.isWhitespace` with a call to the function `Char.isWhitespace`.
```
## Example: single suggestion in namespace
```lean4
example := fun n => n.succ
```
Before:
```
Invalid field notation: Type of
n
is not known; cannot resolve field `succ`
```
The message is unchanged, but this PR adds a hint:
```
Hint: Consider replacing the field projection with a call to one of the following:
• `Fin.succ`
• `Nat.succ`
• `Std.PRange.succ`
```
This PR adds a heterogeneous version of the constructor injectivity
theorems. These theorems are useful for indexed families, and will be
used in `grind`.
This PR adds a module resolution procedure to Lake to disambiguate
modules that are defined in multiple packages.
On an `import`, Lake will now check if multiple packages within the
workspace define the module. If so, it will verify that modules have
sufficiently similar definitions (i.e., artifacts with the same content
hashes). If not, Lake will report an error.
This verification is currently only done for direct imports. Transitive
imports are not checked for consistency. An overhaul of transitive
imports will come later.
This PR fixes a bug in `grind?`. The suggestion using the `grind`
interactive mode was dropping the configuration options provided by the
user. In the following account, the third suggestion was dropping the
`-reducible` option.
```lean
/--
info: Try these:
[apply] grind -reducible only [Equiv.congr_fun, #5103]
[apply] grind -reducible only [Equiv.congr_fun]
[apply] grind -reducible => cases #5103 <;> instantiate only [Equiv.congr_fun]
-/
example :
(Equiv.sigmaCongrRight e).trans (Equiv.sigmaEquivProd α₁ β₂)
= (Equiv.sigmaEquivProd α₁ β₁).trans (prodCongrRight e) := by
grind? -reducible [Equiv.congr_fun]
```
This PR adds the `grind` option `reducible` (default: `true`). When
enabled, definitional equality tests expand only declarations marked as
`@[reducible]`.
Use `grind -reducible` to allow expansion of non-reducible declarations
during definitional equality tests.
This option affects only definitional equality; the canonicalizer and
theorem pattern internalization always unfold reducible declarations
regardless of this setting.
This PR refines several error error messages, mostly involving invalid
use of field notation, generalized field notation, and numeric
projection. Provides a new error explanation for field notation.
## Error message changes
In general:
- Uses a slightly different convention for expression-type pairs, where
the expression is always given `indentExpr` and the type is given
`inlineExpr` treatment. This is something of a workaround for the fact
that the `Format` type is awkward for embedding possibly-linebreaking
expressions in not-linebreaking text, which may be a separate issue
worth addressing.
- Tries to give slightly more "why" reasoning — the environment does not
contain `String.parse`, and _therefore you can't project `.parse` from a
`String`_.
Some specific examples:
### No such projection function
```lean4
#check "".parse
```
before:
```
error: Invalid field `parse`: The environment does not contain `String.parse`
""
has type
String
```
after:
```
error: Invalid field `parse`: The environment does not contain `String.parse`, so it is not possible to project the field `parse` from an expression
""
of type `String`
```
### Type does not have the correct form
```lean4
example (x : α) := (foo x).foo
```
before:
```
error: Invalid field notation: Type is not of the form `C ...` where C is a constant
foo x
has type
α
```
after:
```
error: Invalid field notation: Field projection operates on types of the form `C ...` where C is a constant. The expression
foo x
has type `α` which does not have the necessary form.
```
## Refactoring
Includes some refactoring changes as well:
- factors out multiple uses of number (1, 2, 3, 212, 222) to ordinal
("first", "second", "third", "212th", "222nd") conversion into
Lean.Elab.ErrorUtils
- significant refactoring of `resolveLValAux` in `Lean.Elab.App` — in
place of five helper functions, a special-case function case analysis,
and a case analysis on the projection type and structure, there's now a
single case analysis on the projection type and structure. This allows
several error messages to be more explicit (there were a number of cases
where index projection was being described as field projection in an
error messages) and gave the opportunity to slightly improve positining
for several errors: field *notation* errors should appear on `foo.bar`,
but field *projection* errors should appear only on the `bar` part of
`foo.bar`.
This PR moves the processing of options passed to the CLI from
`shell.cpp` to `Shell.lean`.
As with previous ports, this attempts to mirror as much of the original
behavior as possible, Benefits to be gained from the ported code can
come in later PRs. There should be no significant behavioral changes
from this port. Nonetheless, error reporting has changed some, hopefully
for the better. For instance, errors for improper argument
configurations has been made more consistent (e.g., Lean will now error
if numeric arguments fall outside the expected range for an option).
(Redo of #11345 to fix Windows issue.)
This PR generalizes the `noConfusion` constructions to heterogeneous
equalities (assuming propositional equalities between the indices). This
lays ground work for better support for applying injection to
heterogeneous equalities in grind.
The `Meta.mkNoConfusion` app builder shields most of the code from these
changes.
Since the per-constructor noConfusion principles are now more
expressive, `Meta.mkNoConfusion` no longer uses the general one.
In `Init.Prelude` some proofs are more pedestrian because `injection`
now needs a bit more machinery.
This is a breaking change for whoever uses the `noConfusion` principle
manually and explicitly for a type with indices.
Fixes#11450.
This PR adds lemmas stating that if a get operation returns a value,
then the queried key must be contained in the collection. These lemmas
are added for HashMap and TreeMap-based collections, with a similar
lemma also added for `Init.getElem`.
This PR adapts the lambda lifter in LCNF to eta contract instead of
lambda lift if possible. This prevents the creation of a few hundred
unnecessary lambdas across the code base.
This PR moves the `Inhabited` instances in constant `DTreeMap` (and
related) queries, such as `Const.get!`, where the `Inhabited` instance
can be provided before proving a key.
This PR fixes a panic in `getEqnsFor?` when called on matchers generated
from match expressions in theorem types.
When a theorem's type contains a match expression (e.g., `theorem bar :
(match ... with ...) = 0`), the compiler generates a matcher like
`bar.match_1`. Calling `getEqnsFor?` on this matcher would panic with:
```
PANIC: duplicate normalized declaration name bar.match_1.eq_1 vs. _private...bar.match_1.eq_1
```
This also affected the `try?` tactic, which internally uses
`getEqnsFor?`.
We make `shouldGenerateEqnThms` return `false` for matchers, since their
equations are already generated separately by
`Lean.Meta.Match.MatchEqs`. This prevents the equation generation
machinery from attempting to create duplicate equation theorems.
Closes#11461Closes#10390🤖 Prepared with Claude Code
Co-authored-by: Claude <noreply@anthropic.com>
This PR fixes various typos across the codebase in documentation and
comments.
- `infered` → `inferred` (ParserCompiler.lean)
- `declartation` → `declaration` (Cleanup.lean)
- `certian` → `certain` (CasesInfo.lean)
- `wil` → `will` (Cache.lean)
- `the the` → `the` (multiple files - PrefixTree.lean, Sum/Basic.lean,
List/Nat/Perm.lean, Time.lean, Bounded.lean, Lake files)
- `to to` → `to` (MutualInductive.lean, simp_bubblesort_256.lean)
- Grammar improvements in Bounded.lean and Time.lean
All changes are to comments and documentation only - no functional
changes.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-authored-by: Claude <noreply@anthropic.com>
This PR adds `+suggestions` support to `solve_by_elim`, following the
pattern established by `grind +suggestions` and `simp_all +suggestions`.
Gracefully handles invalid/nonexistent suggestions by filtering them out
🤖 Prepared with Claude Code
Co-authored-by: Claude <noreply@anthropic.com>
This PR adds `solve_by_elim` as a fallback in the `try?` tactic's simple
tactics. When `rfl` and `assumption` both fail but `solve_by_elim`
succeeds (e.g., for goals requiring hypothesis chaining or
backtracking), `try?` will now suggest `solve_by_elim`.
The structure is `first | (attempt_all | rfl | assumption) |
solve_by_elim`, so `solve_by_elim` only runs when the faster tactics
fail.
This is a prerequisite for removing the "first pass" `solve_by_elim`
from `apply?`. Currently `apply?` calls `solve_by_elim` twice: once
before library search, and once after each lemma application. The first
pass can be removed once `try?` includes `solve_by_elim`.
🤖 Prepared with Claude Code
---------
Co-authored-by: Claude <noreply@anthropic.com>
This PR removes the "first pass" behavior where `exact?` and `apply?`
would try `solve_by_elim` on the original goal before doing library
search. This simplifies the `librarySearch` API and focuses these
tactics on their primary purpose: finding library lemmas.
Users who want to find proofs using local hypotheses should use `try?`
instead, which now includes `solve_by_elim` in its pipeline (see
https://github.com/leanprover/lean4/pull/11462).
Changes:
- Removed first pass from `librarySearch`
- Simplified `tactic` parameter from `Bool → List MVarId → MetaM (List
MVarId)` to `List MVarId → MetaM (List MVarId)`
- Updated test expectations
🤖 Prepared with Claude Code
---------
Co-authored-by: Claude <noreply@anthropic.com>
This PR improves the error message when no library suggestions engine is
registered to recommend importing `Lean.LibrarySuggestions.Default` for
the built-in engine.
**Before:**
```
No library suggestions engine registered. (Note that Lean does not provide a default library suggestions engine, these must be provided by a downstream library, and configured using `set_library_suggestions`.)
```
**After:**
```
No library suggestions engine registered. (Add `import Lean.LibrarySuggestions.Default` to use Lean's built-in engine, or use `set_library_suggestions` to configure a custom one.)
```
🤖 Prepared with Claude Code
Co-authored-by: Claude <noreply@anthropic.com>
This PR adds recording functionality such that `shake` can more
precisely track whether an import should be preserved solely for its
`attribute` commands.
This PR adds the difference operation on `DTreeMap`/`TreeMap`/`TreeSet`
and proves several lemmas about it.
---------
Co-authored-by: Markus Himmel <markus@himmel-villmar.de>
The bench script expected no output on stdout from `compile.sh`, which
was not always the case. Now, it separates the compilation and size
measurement steps.
This PR slightly improves the types involved in creating boxed
declarations. Previously the type of
the vdecl used for the return was always `tobj` when returning a boxed
scalar. This is not the most
precise annotation we can give.
This PR modifies the error message for type synthesis failure for the
case where the type class in question is potentially derivable using a
`deriving` command. Also changes the error explanation for type class
instance synthesis failure with an illustration of this pattern.
## Example
```lean4
inductive MyColor where
| chartreuse | sienna | thistle
def forceColor (oc : Option MyColor) :=
oc.get!
```
Before this PR, this gives the potentially confusing impression that
Lean may have decided that `MyColor` is _not_ inhabited — people used to
Rust may be especially inclined towards this confusion.
```
failed to synthesize instance of type class
Inhabited MyColor
Hint: Type class instance resolution failures can be inspected with the `set_option trace.Meta.synthInstance true` command.
```
After this PR, a targeted hint suggests precisely the command that will
fix the issue:
```
error: failed to synthesize instance of type class
Inhabited MyColor
Hint: Adding the command `deriving instance Inhabited for MyColor` may allow Lean to derive the missing instance.
```
This PR lets recursive functions defined by well-founded recursion use a
different `fix` function when the termination measure is of type `Nat`.
This fix-point operator use structural recursion on “fuel”, initialized
by the given measure, and is thus reasonable to reduce, e.g. in `by
decide` proofs.
Extra provisions are in place that the fixpoint operator only starts
reducing when the fuel is fully known, to prevent “accidential” defeqs
when the remaining fuel for the recursive calls match the initial fuel
for that recursive argument.
To opt-out, the idiom `termination_by (n,0)` can be used.
We still use `@[irreducible]` as the default for such recursive
definitions, to avoid unexpected `defeq` lemmas. Making these functions
`@[semireducible]` by default showed performance regressions in lean.
When the measure is of type `Nat`, the system will accept an explicit
`@[semireducible]` without the usual warning.
Fixes#5234. Fixes: #11181.
This PR performs minor maintenance on the String API
- Rename `String.Pos.toCopy` to `String.Pos.copy` to adhere to the
naming convention
- Rename `String.Pos.extract` to `String.extract` to get sane dot
notation again
- Add `String.Slice.Pos.extract`
This PR reduces the memory consumption of the language server (the
watchdog process in particular). In Mathlib, it reduces memory
consumption by about 1GB.
It also fixes two bugs in the call hierarchy:
- When an open file had import errors (e.g. from a transitive build
failure), the call hierarchy would not display any usages in that file.
Now we use the reference information from the .ilean instead.
- When a command would not set a parent declaration (e.g. `#check`), the
result was filtered from the call hierarchy. Now we display it as
`[anonymous]` instead.
This PR documents the `grind_pattern` command for manually selecting
theorem instantiation patterns, including multi-patterns and the
constraint system (`=/=`, `=?=`, `size`, `depth`, `is_ground`,
`is_value`, `is_strict_value`, `gen`, `max_insts`, `guard`, `check`).
@@ -29,6 +29,38 @@ After rebuilding, LSP diagnostics may be stale until the user interacts with fil
If the user expresses frustration with you, stop and ask them to help update this `.claude/CLAUDE.md` file with missing guidance.
## Creating pull requests.
## Creating pull requests
All PRs must have a first paragraph starting with "This PR". This paragraph is automatically incorporated into release notes. Read `lean4/doc/dev/commit_convention.md` when making PRs.
Follow the commit convention in `doc/dev/commit_convention.md`.
**Title format:**`<type>: <subject>` where type is one of: `feat`, `fix`, `doc`, `style`, `refactor`, `test`, `chore`, `perf`.
Subject should use imperative present tense ("add" not "added"), no capitalization, no trailing period.
**Body format:** The first paragraph must start with "This PR". This paragraph is automatically incorporated into release notes. Use imperative present tense. Include motivation and contrast with previous behavior when relevant.
Example:
```
feat: add optional binder limit to `mkPatternFromTheorem`
This PR adds a `num?` parameter to `mkPatternFromTheorem` to control how many
leading quantifiers are stripped when creating a pattern.
```
**Changelog labels:** Add one `changelog-*` label to categorize the PR for release notes:
-`changelog-language` - Language features and metaprograms
-`changelog-tactics` - User facing tactics
-`changelog-server` - Language server, widgets, and IDE extensions
-`changelog-pp` - Pretty printing
-`changelog-library` - Library
-`changelog-compiler` - Compiler, runtime, and FFI
-`changelog-lake` - Lake
-`changelog-doc` - Documentation
-`changelog-ffi` - FFI changes
-`changelog-other` - Other changes
-`changelog-no` - Do not include this PR in the release changelog
If you're unsure which label applies, it's fine to omit the label and let reviewers add it.
## CI Log Retrieval
When CI jobs fail, investigate immediately - don't wait for other jobs to complete. Individual job logs are often available even while other jobs are still running. Try `gh run view <run-id> --log` or `gh run view <run-id> --log-failed`, or use `gh run view <run-id> --job=<job-id>` to target the specific failed job. Sleeping is fine when asked to monitor CI and no failures exist yet, but once any job fails, investigate that failure immediately.
For subsequent RCs (`-rc2`, etc.) and stable releases, just update the version number in the existing release notes file title.
See `doc/dev/release_checklist.md` section "Writing the release notes" for full details.
## Process
1. Run `script/release_checklist.py {version}` to check the current status
2. **CRITICAL: If preliminary lean4 checks fail, STOP immediately and alert the user**
- Check for: release branch exists, CMake version correct, tag exists, release page exists, release notes exist
- Check for: release branch exists, CMake version correct, tag exists, release page exists, release notes file exists
- **IMPORTANT**: The release page is created AUTOMATICALLY by CI after pushing the tag - DO NOT create it manually
- **IMPORTANT**: For -rc1 releases, release notes must be created before proceeding
- Do NOT create any PRs or proceed with repository updates if these checks fail
3. Create a todo list tracking all repositories that need updates
4. **CRITICAL RULE: You can ONLY run `release_steps.py` for a repository if `release_checklist.py` explicitly says to do so**
@@ -39,6 +81,7 @@ These comments explain the scripts' behavior, which repositories get special han
## Important Notes
- **NEVER merge PRs autonomously** - always wait for the user to merge PRs themselves
- The `release_steps.py` script is idempotent - it's safe to rerun
- The `release_checklist.py` script is idempotent - it's safe to rerun
- Some repositories depend on others (e.g., mathlib4 depends on batteries, aesop, etc.)
@@ -60,6 +103,15 @@ Every time you run `release_checklist.py`, you MUST:
This summary should be provided EVERY time you run the checklist, not just after creating new PRs.
The user needs to see the complete picture of what's waiting for review.
## Nightly Infrastructure
The nightly build system uses branches and tags across two repositories:
- `leanprover/lean4` has **branches** `nightly` and `nightly-with-mathlib` tracking the latest nightly builds
- `leanprover/lean4-nightly` has **dated tags** like `nightly-2026-01-23`
When a nightly succeeds with mathlib, all three should point to the same commit. Don't confuse these: branches are in the main lean4 repo, dated tags are in lean4-nightly.
## Error Handling
**CRITICAL**: If something goes wrong or a command fails:
echo "... and Batteries has a 'nightly-testing-$MOST_RECENT_NIGHTLY' tag."
if [[ -n "$MATHLIB_REMOTE_TAGS" ]]; then
echo "... and Mathlib has a 'nightly-testing-$MOST_RECENT_NIGHTLY' tag."
MESSAGE=""
if [[ -n "$MATHLIB_REMOTE_TAGS" ]]; then
echo "... and Mathlib has a 'nightly-testing-$MOST_RECENT_NIGHTLY' tag."
else
echo "... but Mathlib does not yet have a 'nightly-testing-$MOST_RECENT_NIGHTLY' tag."
MESSAGE="- ❗ Mathlib CI can not be attempted yet, as the \`nightly-testing-$MOST_RECENT_NIGHTLY\` tag does not exist there yet. We will retry when you push more commits. If you rebase your branch onto \`nightly-with-mathlib\`, Mathlib CI should run now."
fi
else
echo "... but Batteries does not yet have a 'nightly-testing-$MOST_RECENT_NIGHTLY' tag."
MESSAGE="- ❗ Batteries CI can not be attempted yet, as the \`nightly-testing-$MOST_RECENT_NIGHTLY\` tag does not exist there yet. We will retry when you push more commits. If you rebase your branch onto \`nightly-with-mathlib\`, Batteries CI should run now."
echo "... but Mathlib does not yet have a 'nightly-testing-$MOST_RECENT_NIGHTLY' tag."
MESSAGE="- ❗ Mathlib CI can not be attempted yet, as the \`nightly-testing-$MOST_RECENT_NIGHTLY\` tag does not exist there yet. We will retry when you push more commits. If you rebase your branch onto \`nightly-with-mathlib\`, Mathlib CI should run now."
fi
else
echo "The most recently nightly tag on this branch has SHA: $NIGHTLY_SHA"
@@ -195,8 +216,9 @@ jobs:
if [[ -n "$MESSAGE" ]]; then
# Check if force-mathlib-ci label is present
# Use GITHUB_TOKEN for read-only label fetch (MATHLIB4_COMMENT_BOT is only for posting comments)
NOTE: The current interface was designed for internal use in Lean and should be considered **unstable**.
It will be refined and extended in the future.
The Lean FFI documentation is now part of the [Lean language reference](https://lean-lang.org/doc/reference/latest/).
As Lean is written partially in Lean itself and partially in C++, it offers efficient interoperability between the two languages (or rather, between Lean and any language supporting C interfaces).
This support is however currently limited to transferring Lean data types; in particular, it is not possible yet to pass or return compound data structures such as C `struct`s by value from or to Lean.
There are two primary attributes for interoperating with other languages:
*`@[extern "sym"] constant leanSym : ...` binds a Lean declaration to the external symbol `sym`.
It can also be used with `def` to provide an internal definition, but ensuring consistency of both definitions is up to the user.
*`@[export sym] def leanSym : ...` exports `leanSym` under the unmangled symbol name `sym`.
For simple examples of how to call foreign code from Lean and vice versa, see <https://github.com/leanprover/lean4/blob/master/src/lake/examples/ffi> and <https://github.com/leanprover/lean4/blob/master/src/lake/examples/reverse-ffi>, respectively.
## The Lean ABI
The Lean Application Binary Interface (ABI) describes how the signature of a Lean declaration is encoded as a native calling convention.
It is based on the standard C ABI and calling convention of the target platform.
For a Lean declaration marked with either `@[extern "sym"]` or `@[export sym]` for some symbol name `sym`, let `α₁ → ... → αₙ → β` be the normalized declaration's type.
If `n` is 0, the corresponding C declaration is
```c
externssym;
```
where `s` is the C translation of `β` as specified in the next section.
In the case of an `@[extern]` definition, the symbol's value is guaranteed to be initialized only after calling the Lean module's initializer or that of an importing module; see [Initialization](#initialization).
If `n` is greater than 0, the corresponding C declaration is
```c
ssym(t₁,...,tₘ);
```
where the parameter types `tᵢ` are the C translation of the `αᵢ` as in the next section.
In the case of `@[extern]` all *irrelevant* types are removed first; see next section.
### Translating Types from Lean to C
* The integer types `UInt8`, ..., `UInt64`, `USize` are represented by the C types `uint8_t`, ..., `uint64_t`, `size_t`, respectively
*`Char` is represented by `uint32_t`
*`Float` is represented by `double`
* An *enum* inductive type of at least 2 and at most 2^32 constructors, each of which with no parameters, is represented by the first type of `uint8_t`, `uint16_t`, `uint32_t` that is sufficient to represent all constructor indices.
For example, the type `Bool` is represented as `uint8_t` with values `0` for `false` and `1` for `true`.
*`Decidable α` is represented the same way as `Bool`
* An inductive type with a *trivial structure*, that is,
* it is none of the types described above
* it is not marked `unsafe`
* it has a single constructor with a single parameter of *relevant* type
is represented by the representation of that parameter's type.
For example, `{ x : α // p }`, the `Subtype` structure of a value of type `α` and an irrelevant proof, is represented by the representation of `α`.
Similarly, the signed integer types `Int8`, ..., `Int64`, `ISize` are also represented by the unsigned C types `uint8_t`, ..., `uint64_t`, `size_t`, respectively, because they have a trivial structure.
* `Nat` and `Int` are represented by `lean_object *`.
Their runtime values is either a pointer to an opaque bignum object or, if the lowest bit of the "pointer" is 1 (`lean_is_scalar`), an encoded unboxed natural number or integer (`lean_box`/`lean_unbox`).
* A universe `Sort u`, type constructor `... → Sort u`, `Void α` or proposition `p : Prop` is *irrelevant* and is either statically erased (see above) or represented as a `lean_object *` with the runtime value `lean_box(0)`
* Any other type is represented by `lean_object *`.
Its runtime value is a pointer to an object of a subtype of `lean_object` (see the "Inductive types" section below) or the unboxed value `lean_box(cidx)` for the `cidx`th constructor of an inductive type if this constructor does not have any relevant parameters.
Example: the runtime value of `u : Unit` is always `lean_box(0)`.
#### Inductive types
For inductive types which are in the fallback `lean_object *` case above and not trivial constructors, the type is stored as a `lean_ctor_object`, and `lean_is_ctor` will return true. A `lean_ctor_object` stores the constructor index in the header, and the fields are stored in the `m_objs` portion of the object.
The memory order of the fields is derived from the types and order of the fields in the declaration. They are ordered as follows:
* Non-scalar fields stored as `lean_object *`
* Fields of type `USize`
* Other scalar fields, in decreasing order by size
Within each group the fields are ordered in declaration order. Trivial wrapper types count as their underlying wrapped type for this purpose.
* To access fields of the first kind, use `lean_ctor_get(val, i)` to get the `i`th non-scalar field.
* To access `USize` fields, use `lean_ctor_get_usize(val, n+i)` to get the `i`th usize field and `n` is the total number of fields of the first kind.
* To access other scalar fields, use `lean_ctor_get_uintN(val, off)` or `lean_ctor_get_usize(val, off)` as appropriate. Here `off` is the byte offset of the field in the structure, starting at `n*sizeof(void*)` where `n` is the number of fields of the first two kinds.
For example, a structure such as
```lean
structure S where
ptr_1 : Array Nat
usize_1 : USize
sc64_1 : UInt64
sc64_2 : { x : UInt64 // x > 0 } -- wrappers of scalars count as scalars
sc64_3 : Float -- `Float` is 64 bit
sc8_1 : Bool
sc16_1 : UInt16
sc8_2 : UInt8
sc64_4 : UInt64
usize_2 : USize
sc32_1 : Char -- trivial wrapper around `UInt32`
sc32_2 : UInt32
sc16_2 : UInt16
```
would get re-sorted into the following memory order:
By default, all `lean_object *` parameters of an `@[extern]` function are considered *owned*, i.e. the external code is passed a "virtual RC token" and is responsible for passing this token along to another consuming function (exactly once) or freeing it via `lean_dec`.
To reduce reference counting overhead, parameters can be marked as *borrowed* by prefixing their type with `@&`.
Borrowed objects must only be passed to other non-consuming functions (arbitrarily often) or converted to owned values using `lean_inc`.
In `lean.h`, the `lean_object *` aliases `lean_obj_arg` and `b_lean_obj_arg` are used to mark this difference on the C side.
Return values and `@[export]` parameters are always owned at the moment.
## Initialization
When including Lean code as part of a larger program, modules must be *initialized* before accessing any of their declarations.
Module initialization entails
* initialization of all "constants" (nullary functions), including closed terms lifted out of other functions
* execution of all `[init]` functions
* execution of all `[builtin_init]` functions, if the `builtin` parameter of the module initializer has been set
The module initializer is automatically run with the `builtin` flag for executables compiled from Lean code and for "plugins" loaded with `lean --plugin`.
For all other modules imported by `lean`, the initializer is run without `builtin`.
Thus `[init]` functions are run iff their module is imported, regardless of whether they have native code available or not, while `[builtin_init]` functions are only run for native executable or plugins, regardless of whether their module is imported or not.
`lean` uses built-in initializers for e.g. registering basic parsers that should be available even without importing their module (which is necessary for bootstrapping).
The initializer for module `A.B` in a package `foo` is called `initialize_foo_A_B`. For modules in the Lean core (e.g., `Init.Prelude`), the initializer is called `initialize_Init_Prelude`. Module initializers will automatically initialize any imported modules. They are also idempotent (when run with the same `builtin` flag), but not thread-safe.
**Important for process-related functionality**: If your application needs to use process-related functions from libuv, such as `Std.Internal.IO.Process.getProcessTitle` and `Std.Internal.IO.Process.setProcessTitle`, you must call `lean_setup_args(argc, argv)` (which returns a potentially modified `argv` that must be used in place of the original) **before** calling `lean_initialize()` or `lean_initialize_runtime_module()`. This sets up process handling capabilities correctly, which is essential for certain system-level operations that Lean's runtime may depend on.
Together with initialization of the Lean runtime, you should execute code like the following exactly once before accessing any Lean declarations:
```c
void lean_initialize_runtime_module();
void lean_initialize();
char ** lean_setup_args(int argc, char ** argv);
lean_object * initialize_A_B(uint8_t builtin);
lean_object * initialize_C(uint8_t builtin);
...
argv = lean_setup_args(argc, argv); // if using process-related functionality
lean_initialize_runtime_module();
//lean_initialize(); // necessary (and replaces `lean_initialize_runtime_module`) if you (indirectly) access the `Lean` package
lean_object * res;
// use same default as for Lean executables
uint8_t builtin = 1;
res = initialize_A_B(builtin);
if (lean_io_result_is_ok(res)) {
lean_dec_ref(res);
} else {
lean_io_result_show_error(res);
lean_dec(res);
return ...; // do not access Lean declarations if initialization failed
}
res = initialize_C(builtin);
if (lean_io_result_is_ok(res)) {
...
//lean_init_task_manager(); // necessary if you (indirectly) use `Task`
lean_io_mark_end_initialization();
```
In addition, any other thread not spawned by the Lean runtime itself must be initialized for Lean use by calling
```c
void lean_initialize_thread();
```
and should be finalized in order to free all thread-local resources by calling
```c
void lean_finalize_thread();
```
## `@[extern]` in the Interpreter
The interpreter can run Lean declarations for which symbols are available in loaded shared libraries, which includes `@[extern]` declarations.
Thus to e.g. run `#eval` on such a declaration, you need to
1. compile (at least) the module containing the declaration and its dependencies into a shared library, and then
1. pass this library to `lean --load-dynlib=` to run code `import`ing this module.
Note that it is not sufficient to load the foreign library containing the external symbol because the interpreter depends on code that is emitted for each `@[extern]` declaration.
Thus it is not possible to interpret an `@[extern]` declaration in the same file.
See [`tests/compiler/foreign`](https://github.com/leanprover/lean4/tree/master/tests/compiler/foreign/) for an example.
.text"The Lean standard library contains a fully-featured string library, centered around the types `String` and `String.Slice`.",
.text"`String` is defined as the subtype of `ByteArray` of valid UTF-8 strings. A `String.Slice` is a `String` together with a start and end position.",
.text"`String` is equivalent to `List Char`, but it has a more efficient runtime representation. While the logical model based on `ByteArray` is overwritten in the runtime, the runtime implementation is very similar to the logical model, with the main difference being that the length of a string in Unicode code points is cached in the runtime implementation.",
.text"We are considering removing this feature in the future (i.e., deprecating `String.length`), as the number of UTF-8 codepoints in a string is not particularly useful, and if needed it can be computed in linear time using `s.positions.count`."
.text"The Lean standard library contains a number of functions that take one or more strings and slices and return a string or a slice.",
.text"If possible, these functions should avoid allocating a new string, and return a slice of their input(s) instead.",
.text"Usually, for every operation `f`, there will be functions `String.f` and `String.Slice.f`, where `String.f s` is defined as `String.Slice.f s.toSlice`.",
.text"In particular, functions that transform strings and slices should live in the `String` and `String.Slice` namespaces even if they involve a `String.Pos`/`String.Slice.Pos` (like `String.sliceTo`), for reasons that will become clear shortly.",
.h3"Transforming positions",
.text"Since positions on strings and slices are dependent on the string or slice, whenever users transform a string/slice, they will be interested in interpreting positions on the original string/slice as positions on the result, or vice versa.",
.text"Consequently, every operation that transforms a string or slice should come with a corresponding set of transformations between positions, usually in both directions, possibly with one of the directions being conditional.",
.text"For example, given a string `s` and a position `p` on `s`, we have the slice `s.sliceFrom p`, which is the slice from `p` to the end of `s`. A position on `s.sliceFrom p` can always be interpreted as a position on `s`. This is the \"backwards\" transformation. Conversely, a position `q` on `s` can be interpreted as a position on `s.sliceFrom p` as long as `p ≤ q`. This is the conditional forwards direction.",
.text"The convention for naming these transformations is that the forwards transformation should have the same name as the transformation on strings/slices, but it should be located in the `String.Pos` or `String.Slice.Pos` namespace, depending on the type of the starting position (so that dot notation is possible for the forward direction). The backwards transformation should have the same name as the operation on strings/slices, but with an `of` prefix, and live in the same namespace as the forwards transformation (so in general dot notation will not be available).",
.text"So, in the `sliceFrom` example, the forward direction would be called `String.Pos.sliceFrom`, while the backwards direction should be called `String.Pos.ofSliceFrom` (not `String.Slice.Pos.ofSliceFrom`).",
.text"If one of the directions is conditional, it should have a corresponding panicking operation that does not require a proof; in our example this would be `String.Pos.sliceFrom!`.",
.text"Sometimes there is a name clash for the panicking operations if the operation on strings is already panicking. For example, there are both `String.slice` and `String.slice!`. If the original operation is already panicking, we only provide panicking transformation operations. But now `String.Pos.slice!` could refer both to the panicking forwards transformation associated with `String.slice`, and also to the (only) forwards transformation associated with `String.slice!`. In this situation, we use an `orPanic` suffix to disambiguate. So the panicking forwards operation associated with `String.slice` is called `String.Pos.sliceOrPanic`, and the forwards operation associated with `String.slice!` is called `String.Pos.slice!`."
Some files were not shown because too many files have changed in this diff
Show More
Reference in New Issue
Block a user
Blocking a user prevents them from interacting with repositories, such as opening or commenting on pull requests or issues. Learn more about blocking a user.
