lean4-htt/tests/elab/grind_inst_mvars_issue.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

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namespace Nat
def ascFactorial (n : Nat) : Nat → Nat
| 0 => 1
| k + 1 => (n + k) * ascFactorial n k
def descFactorial (n : Nat) : Nat → Nat
| 0 => 1
| k + 1 => (n - k) * descFactorial n k
theorem descFactorial_of_lt {n : Nat} : ∀ {k : Nat}, n < k → n.descFactorial k = 0 := by sorry
theorem add_descFactorial_eq_ascFactorial' (n : Nat) :
∀ k : Nat, (n + k - 1).descFactorial k = n.ascFactorial k := by sorry
def ascFactorialBinary (n k : Nat) : Nat :=
match k with
| 0 => 1
| 1 => n
| k@(_ + 2) => ascFactorialBinary n (k / 2) * ascFactorialBinary (n + k / 2) ((k + 1) / 2)
theorem ascFactorial_eq_ascFactorialBinary : ascFactorial = ascFactorialBinary := sorry
def descFactorialBinary (n k : Nat) : Nat :=
if n < k then 0
else ascFactorialBinary (n - k + 1) k
theorem descFactorial_eq_descFactorialBinary : descFactorial = descFactorialBinary := by
ext n k
rw [descFactorialBinary]
split <;> rename_i h
· rw [descFactorial_of_lt h]
· rw [← ascFactorial_eq_ascFactorialBinary, ← add_descFactorial_eq_ascFactorial']
grind
end Nat