This PR takes a more principled approach in deriving `String` pattern
lemmas by reducing to simpler cases similar to how the instances are
defined.
This reduces duplication of complex arguments (at the expense of having
to state more simple lemmas; however these lemmas are useful to users as
well).
This PR adds a `set_option cbv.maxSteps N` option that controls the
maximum
number of simplification steps the `cbv` tactic performs. Previously the
limit
was hardcoded to the `Sym.Simp.Config` default of 100,000 with no way
for
users to override it. The option is threaded through `cbvCore`,
`cbvEntry`,
`cbvGoal`, and `cbvDecideGoal`.
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---------
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
This PR moves cbv tests to the correct test directories. `cbv4.lean` is
a
straightforward elaboration test and is moved to `tests/elab/`. The AES
and ARM
load/store tests are performance-oriented stress tests and are moved to
`tests/elab_bench/`.
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
This PR makes the compiler removes arguments to join points that are
void, avoiding a bunch of dead
stores in the bytecode and the initial C (though LLVM was surely able to
optimize these away further
down the line already).
This PR introduces the core HTTP data types: `Request`, `Response`,
`Status`, `Version`, and `Method`. Currently, URIs are represented as
`String` and headers as `HashMap String (Array String)`. These are
placeholders, future PRs will replace them with strict implementations.
This contains the same code as #10478, divided into separate pieces to
facilitate easier review.
The pieces of this feature are:
- Core data structures: #12126
- Headers: #12127
- URI: #12128
- Body: #12144
- H1: #12146
- Server: #12151
- Client:
---------
Co-authored-by: Rob23oba <152706811+Rob23oba@users.noreply.github.com>
This PR skips the noncomputable pre-check in `processDefDeriving` when
the instance type is `Prop`. Since proofs are erased by the compiler,
computability is irrelevant for `Prop`-valued instances.
Previously (since https://github.com/leanprover/lean4/pull/12756),
`deriving instance` would reject instances that transitively depend on
noncomputable definitions, even when the class extends `Prop`. This came
up in mathlib where `Precoverage.IsStableUnderBaseChange` (a `Prop`
class) needs `deriving noncomputable instance` unnecessarily.
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This PR fixes `release_steps.py` for `verso`. After running `lake
update` in the root, the `test-projects/*/lake-manifest.json` files
retain stale subverso pins, causing verso's "SubVerso version
consistency" CI check to fail. The fix syncs the root manifest's
subverso rev into all test-project sub-manifests.
Root cause: verso has nested Lake projects in `test-projects/` each with
their own `lake-manifest.json`. Running `lake update` in the root
updates the root manifest but doesn't touch the nested ones.
🤖 Prepared with Claude Code
---------
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
This PR adds high priority to instances for `OfSemiring.Q` in the grind
ring envelope. When Mathlib is imported, instance synthesis for types
like `OfSemiring.Q Nat` becomes very expensive because the solver
explores many irrelevant paths before finding the correct instances. By
marking these instances as high priority and adding shortcut instances
for basic operations (`Add`, `Sub`, `Mul`, `Neg`, `OfNat`, `NatCast`,
`IntCast`, `HPow`), instance synthesis resolves quickly.
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---------
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
Co-authored-by: Kim Morrison <kim@tqft.net>
This PR fixes `release_checklist.py` to report failing CI checks
immediately, even when other checks are still in progress. Previously,
having any in-progress checks would return `"pending"` status, masking
failures that had already occurred. Now it returns `"failure"` with a
message like `"1 check(s) failing, 2 still in progress"`.
Also adds a section to `.claude/commands/release.md` instructing the AI
assistant to investigate any CI failure immediately rather than
reporting it as "in progress" and moving on.
🤖 Prepared with Claude Code
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This PR fixes a parsing bug in \`release_checklist.py\` introduced by
https://github.com/leanprover/lean4/pull/12700, which reformatted
\`src/CMakeLists.txt\` to use \`CACHE STRING \"\"\`:
\`\`\`cmake
set(LEAN_VERSION_MINOR 30 CACHE STRING "")
\`\`\`
The old code used \`split()[-1].rstrip(")")\` to extract the version
number, which now yields \`""\` (the empty string argument) instead of
the minor version. Use a regex to extract the digit directly.
🤖 Prepared with Claude Code
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
This PR adds user-facing API lemmas for `s.contains t`, where `s` and
`t` are both a string or a slice.
Under the hood these lemmas are backed by the correctness proof for KMP
that was added a few weeks ago.
This PR fixes a CMake scoping bug that made `-DLEAN_VERSION_*` overrides
ineffective.
The version variables (`LEAN_VERSION_MAJOR`, `MINOR`, `PATCH`,
`IS_RELEASE`) were declared with plain `set()`, which creates normal
variables that shadow cache variables set by `-D` on the command line.
The fix changes them to `CACHE STRING ""` to match the existing
`LEAN_SPECIAL_VERSION_DESC` pattern.
However, `CACHE STRING ""` alone isn't sufficient because `project(LEAN
CXX C)` implicitly creates empty `LEAN_VERSION_{MAJOR,MINOR,PATCH}`
normal variables (CMake sets `<PROJECT>_VERSION_*` for the project
name). These shadow the cache values, so we `unset()` them after the
cache declarations to let `${VAR}` fall through to the cache.
Closes https://github.com/leanprover/lean4/issues/12681🤖 Prepared with Claude Code
---------
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
This PR replaces `lean.code-workspace` with standard `.vscode/`
configuration
files (`settings.json`, `tasks.json`, `extensions.json`). The workspace
file
required users to explicitly "Open Workspace from File" (and moreover
gives a
noisy prompt whether or not they want to open it), while `.vscode/`
settings
are picked up automatically when opening the folder. This became
possible after
#12652 reduced the workspace to a single folder.
Also drops the `rewrap.wrappingColumn` markdown setting, as the Rewrap
extension
is no longer signed on the VS Code marketplace.
🤖 Prepared with Claude Code
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
This PR deprecates `levelZero` in favor of `Level.zero` and `levelOne`
in favor of the new `Level.one`, and updates all usages throughout the
codebase. The `levelZero` alias was previously required for computed
field `data` to work, but this is no longer needed.
🤖 Prepared with Claude Code
This PR adds general projection lemmas for `ExceptConds` conjunction:
- `ExceptConds.and_elim_left`: `(x ∧ₑ y) ⊢ₑ x`
- `ExceptConds.and_elim_right`: `(x ∧ₑ y) ⊢ₑ y`
The existing `and_true`, `true_and`, `and_false`, `false_and` are
refactored as one-line corollaries.
Suggested by @sgraf812 in
https://github.com/leanprover-community/cslib/pull/376#discussion_r2066993469.
🤖 Prepared with Claude Code
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
MacOS uses a very old version of bash where `"${FOO[@]}"` fails if `set
-u` is enabled and `FOO` is undefined. Newer versions of bash expand
this to zero arguments instead.
Also, `lint.py` used the shebang `#!/usr/bin/env python` instead of
`python3`, which fails on some systems.
In CI, all macos tests run on nscloud runners. Presumably, they have
installed newer versions of various software, hence this didn't break in
CI.
This PR fixes `@[implicit_reducible]` on well-founded recursive
definitions.
`addPreDefAttributes` sets WF-recursive definitions as `@[irreducible]`
by default, skipping this only when the user explicitly wrote
`@[reducible]` or `@[semireducible]`. It was missing
`@[instance_reducible]` and `@[implicit_reducible]`, causing those
attributes to be silently overridden.
Add `instance_reducible` and `implicit_reducible` to the check in
`src/Lean/Elab/PreDefinition/Mutual.lean` that guards against overriding
user-specified reducibility attributes, and add regression tests in
`tests/elab/wfirred.lean`.
## Example
```lean
-- Before fix: printed @[irreducible] def f : List Nat → Nat
-- After fix: printed @[implicit_reducible] def f : List Nat → Nat
@[instance_reducible] def f : ∀ _l : List Nat, Nat
| [] => 0
| [_x] => 1
| x :: y :: l => if h : x = y then f (x :: l) else f l + 2
termination_by l => sizeOf l
#print sig f
```
Fixes#12775
---------
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: nomeata <148037+nomeata@users.noreply.github.com>
This PR provides a `ForwardPatternModel` for string patterns and deduces
theorems and lawfulness instances from the corresponding results for
slice patterns.
This PR fixes an inconsistency in `getStuckMVar?` where the instance
argument to class projection functions and auxiliary parent projections
was not whnf-normalized before checking for stuck metavariables. Every
other case in `getStuckMVar?` (recursors, quotient recursors, `.proj`
nodes) normalizes the major argument via `whnf` before recursing — class
projection functions and aux parent projections were the exception.
This bug was identified by Matthew Jasper. When the instance parameter
to a class projection is not normalized, `getStuckMVar?` may fail to
detect stuck metavariables that would be revealed by whnf, or conversely
may report stuckness for expressions that would reduce to constructors.
This caused issues with `OfNat` and `Zero` at
`with_reducible_and_instances` transparency.
Note: PR #12701 (already merged) is also required to fix the original
Mathlib examples.
This PR adds `at` location syntax to the `cbv` tactic, matching the
interface of `simp at`. Previously `cbv` could only reduce the goal
target; now it supports `cbv at h`, `cbv at h |-`, and `cbv at *`.
`cbvGoal` is rewritten to use `Sym.preprocessMVar` followed by `cbvCore`
within a single `SymM` context, sharing the term table across all
hypotheses and the target. The old `cbvGoalCore` (which reduced one side
of an equation goal at a time) is replaced by a general approach that
reduces arbitrary goal types and hypothesis types, with special handling
for `True` targets and `False` hypotheses. `cbvDecideGoal` is updated to
use the extracted `cbvCore` as well.
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---------
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This PR adds a dedicated cbv simproc for `Decidable.decide` that
directly matches on `isTrue`/`isFalse` instances, producing simpler
proof terms and avoiding unnecessary unfolding through `Decidable.rec`.
---------
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
This PR generalizes `String.Slice.Pos.cast`, which turns an `s.Pos` into
a `t.Pos`, to no longer require `s = t`, but merely `s.copy = t.copy`.
This is a breaking change, but one that is easy to adapt to, by
replacing `proof` with `congrArg Slice.copy proof` where required.
This PR adds `deriving noncomputable instance Foo for Bar` syntax so
that delta-derived instances can be marked noncomputable. Previously,
when the underlying instance was noncomputable, `deriving instance`
would fail with an opaque async compilation error.
Now:
- `deriving noncomputable instance Foo for Bar` marks the generated
instance as noncomputable (using `addDecl` + `addNoncomputable` instead
of `addAndCompile`)
- `deriving instance Foo for Bar` pre-checks for noncomputable
dependencies and gives an actionable error with a "Try this:" suggestion
pointing to the noncomputable variant
- For handler-based deriving (inductives/structures), `noncomputable`
sets `isNoncomputable` on the scope
The `optDefDeriving` and `optDeriving` trailing parsers are updated with
`notSymbol "noncomputable"` to prevent them from stealing the parse of
`deriving noncomputable instance ...`.
🤖 Prepared with Claude Code
---------
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
This PR enables Lake to download artifacts from a remote cache service
on demand as part of a `lake build`. It also refactors much of the cache
API to be more type safe.
The newly documented `lake cache add` command loads input-to-output
mappings from a file and stores them in the cache with optional
information about which cache service and what scope they come from.
With this information, Lake can now download artifacts on demand during
a `lake build`.
The `lake cache get` command has also changed its default behavior to
download just the input-to-outputs mapping and then lazily fetch
artifacts from Reservoir as part of a `lake build`. The original eager
behavior can be forced via the new `--download-arts` option.
This PR using `StateT.run` rather than the "defeq abuse" of function
application. There remain many places where we still use function
application for `ReaderT`, but I've updated this in the touched files.
(To really solve this, we would make `StateT` irreducible, but that is
not happening here.)
---------
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
This PR ensures `linter.all` disables `constructorNameAsVariable`.
The issue was discovered by @eric-wieser while investigating a quote4
issue.
This seems like an easy mistake to make when setting up a new linter,
and perhaps we need a better structure to make it easy to do the right
thing.
---------
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
This PR replaces the `isImplicitReducible` check with `Meta.isInstance`
in the `shouldInline` function within `inlineCandidate?`.
At the base phase, we skip inlining instances tagged with
`[inline]`/`[always_inline]`/`[inline_if_reduce]` because their local
functions will be lambda lifted during the base phase. The goal is to
keep instance code compact so the lambda lifter can extract
cheap-to-inline declarations. Inlining instances prematurely expands the
code and creates extra work for the lambda lifter — producing many
additional lambda-lifted closures.
The previous check used `isImplicitReducible`, which does not capture
the original intent: some `instanceReducible` declarations are not
instances. `Meta.isInstance` correctly targets only actual type class
instances. Although `Meta.isInstance` depends on the scoped extension
state, this is safe because `shouldInline` runs during LCNF compilation
at `addDecl` time — any instance referenced in the code was resolved
during elaboration when the scope was active, and LCNF compilation
occurs before the scope changes.
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Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
This PR changes the approach in `simpIteCbv` and `simpDIteCbv`, by
replacing call to `Decidable.decide`
with reducing and direct pattern matching on the `Decidable` instance
for `isTrue`/`isFalse`. This produces simpler proof terms.
---------
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
This PR adds pre-pass simprocs `simpOr` and `simpAnd` to the `cbv`
tactic that evaluate only the left argument of `Or`/`And` first,
short-circuiting when the result is determined without evaluating the
right side. Previously, `cbv` processed `Or`/`And` via congruence, which
always evaluated both arguments. For expressions like `decide (m < n ∨
expensive)`, when `m < n` is true, the expensive right side is now
skipped entirely.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
This PR provides injectivity lemmas for `List.getElem`, `List.getElem?`,
`List.getElem!` and `List.getD` as well as for `Option`. Note: This
introduces a breaking change, changing the signature of
`Option.getElem?_inj`.
This PR adds a section to the /release command explaining how to use `gh
pr checks --watch` to wait for CI or merges without polling.
🤖 Prepared with Claude Code
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
This PR fixes `pp.fvars.anonymous` to display loose free variables as
`_fvar._` instead of `_` when the option is set to `false`. This was the
intended behavior in https://github.com/leanprover/lean4/pull/12688 but
the fix was committed locally and not pushed before that PR was merged.
🤖 Prepared with Claude Code
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This PR switches four lightweight workflows from `pull_request` to
`pull_request_target` to stop GitHub from requiring manual approval when
the
`mathlib-lean-pr-testing[bot]` app triggers label events (e.g. adding
`builds-mathlib`). Since the bot never lands commits on master, it is
perpetually treated as a "first-time contributor" and every
`pull_request`
event it triggers requires approval. `pull_request_target` events always
run
without approval because they execute trusted code from the base branch.
This is safe for all four workflows because none check out or execute
code
from the PR branch — they only read labels, PR body, and file lists from
the
event payload and API:
- `awaiting-mathlib.yml` — checks label combinations
- `awaiting-manual.yml` — checks label combinations
- `pr-body.yml` — checks PR body formatting
- `check-stdlib-flags.yml` — checks if stdlib_flags.h was modified via
API
Also adds explicit `permissions: pull-requests: read` to each workflow
as a
least-privilege hardening measure, since `pull_request_target` has
access to
secrets.
Addresses the issue reported by Sebastian:
https://lean-fro.zulipchat.com/#narrow/channel/398861-general/topic/mathlib.20pr-testing.20breakage.3F/near/575084348🤖 Prepared with Claude Code
---------
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
This PR changes the shebang in `lean_profile.sh` from `#!/bin/bash` to
`#!/usr/bin/env bash` so the script works on NixOS and other systems
where bash is not at `/bin/bash`, and adds a Claude Code skill pointing
to the profiler documentation.
🤖 Prepared with Claude Code
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
This PR gives the `generate` function's "apply @Foo to Goal" trace nodes
their own trace sub-class `Meta.synthInstance.apply` instead of sharing
the parent `Meta.synthInstance` class.
This allows metaprograms that walk synthesis traces to distinguish
instance application attempts from other synthesis nodes by checking
`td.cls` rather than string-matching on the header text.
The new class is registered with `inherited := true`, so `set_option
trace.Meta.synthInstance true` continues to show these nodes.
Motivated by mathlib's `#defeq_abuse` diagnostic tactic
(https://github.com/leanprover-community/mathlib4/pull/35750) which
currently checks `headerStr.contains "apply"` to identify these nodes.
See
https://leanprover.zulipchat.com/#narrow/channel/113488-general/topic/backward.2EisDefEq.2ErespectTransparency🤖 Prepared with Claude Code
---------
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This PR adds a `pp.fvars.anonymous` option (default `true`) that
controls the display of loose free variables (fvars not in the local
context).
- When `true` (default), loose fvars display their internal name like
`_fvar.42`
- When `false`, they display as `_fvar._`
This is analogous to `pp.mvars.anonymous` for metavariables. It's useful
for stabilizing output in `#guard_msgs` when messages contain fvar IDs
that vary between runs — for example, in diagnostic tools that report
`isDefEq` failures from trace output where the local context is not
available.
🤖 Prepared with Claude Code
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
This PR fixes a gap in how `@[implicit_reducible]` is assigned to parent
projections during structure elaboration.
When `class C extends P₁, P₂` has diamond inheritance, some ancestor
structures become constructor subobject fields even though they aren't
direct parents. For example, in `Monoid extends Semigroup, MulOneClass`,
`One` becomes a constructor subobject of `Monoid` — its field `one`
doesn't overlap with `Semigroup`'s fields, and `inSubobject?` is `none`
during `MulOneClass` flattening.
`mkProjections` creates the projection `Monoid.toOne` but defers
reducibility to `addParentInstances` (guarded by `if !instImplicit`).
However, `addParentInstances` only processes direct parents from the
`extends` clause. Grandparent subobject projections fall through the gap
and stay `semireducible`.
This causes defeq failures when `backward.isDefEq.respectTransparency`
is enabled (#12179): at `.instances` transparency, the semireducible
grandparent projection can't unfold, so two paths to the same ancestor
structure aren't recognized as definitionally equal.
Fix: before `addParentInstances`, iterate over all `.subobject` fields
and set `implicitReducible` on those whose parent is a class.
🤖 Prepared with Claude Code
---------
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
The linter was running in parallel with other tests, which were creating
and deleting files. Since the linter was iterating over some files and
directories at the time, it crashed.
