Files
lean4/tests/elab/issue4146.lean
Garmelon 08eb78a5b2 chore: switch to new test/bench suite (#12590)
This PR sets up the new integrated test/bench suite. It then migrates
all benchmarks and some related tests to the new suite. There's also
some documentation and some linting.

For now, a lot of the old tests are left alone so this PR doesn't become
even larger than it already is. Eventually, all tests should be migrated
to the new suite though so there isn't a confusing mix of two systems.
2026-02-25 13:51:53 +00:00

48 lines
1.3 KiB
Lean4

set_option linter.unusedVariables false
def bar (n : Nat) : Bool :=
if h : n = 0 then
true
else
match n with -- NB: the elaborator adds `h` as an discriminant
| m+1 => bar m
termination_by n
-- set_option pp.match false
-- #print bar
-- #check bar.match_1
-- #print bar.induct
-- NB: The induction theorem used to have two `h` in scope, as its original type mentioning `x`,
-- and a refined `h` mentioning `m+1`.
-- At some point we had a HEq between them, but not any more, thanks to proof irrelevance
-- Since #7110, we drop the shadowed `h`.
/--
info: bar.induct (motive : Nat → Prop) (case1 : motive 0) (case2 : ∀ (m : Nat), ¬m + 1 = 0 → motive m → motive m.succ)
(n : Nat) : motive n
-/
#guard_msgs in
#check bar.induct
def baz (n : Nat) (i : Fin (n+1)) : Bool :=
if h : n = 0 then
true
else
match n, i + 1 with
| 1, _ => true
| m+2, j => baz (m+1) j.1-1, by omega
termination_by n
-- #print baz._unary
/--
info: baz.induct (motive : (n : Nat) → Fin (n + 1) → Prop) (case1 : ∀ (i : Fin (0 + 1)), motive 0 i)
(case2 : ¬1 = 0 → ∀ (i : Fin (1 + 1)), motive 1 i)
(case3 :
∀ (m : Nat), ¬m + 2 = 0 → ∀ (i : Fin (m.succ.succ + 1)), motive (m + 1) ⟨↑(i + 1) - 1, ⋯⟩ → motive m.succ.succ i)
(n : Nat) (i : Fin (n + 1)) : motive n i
-/
#guard_msgs in
#check baz.induct