lean4-htt/tests/elab/grind_10160.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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structure PreInt where
minuend : Nat
subtrahend : Nat
/-- Definition 4.1.1 -/
instance PreInt.instSetoid : Setoid PreInt where
r a b := a.minuend + b.subtrahend = b.minuend + a.subtrahend
iseqv := {
refl := by grind
symm := by grind
trans := by grind
}
abbrev MyInt := Quotient PreInt.instSetoid
abbrev MyInt.formalDiff (a b : Nat) : MyInt := Quotient.mk PreInt.instSetoid ⟨ a, b ⟩
theorem MyInt.eq (a b c d : Nat) : formalDiff a b = formalDiff c d ↔ a + d = c + b :=
⟨ Quotient.exact, by intro h; exact Quotient.sound h ⟩
instance MyInt.instOfNat {n : Nat} : OfNat MyInt n where
ofNat := formalDiff n 0
instance MyInt.instNatCast : NatCast MyInt where
natCast n := formalDiff n 0
theorem MyInt.natCast_eq (n : Nat) : (n : MyInt) = formalDiff n 0 := rfl
theorem MyInt.natCast_inj (n m : Nat) :
(n : MyInt) = (m : MyInt) ↔ n = m := by
rw [natCast_eq, natCast_eq, eq]; simp
example (n m : Nat) : (n : MyInt) = (m : MyInt) ↔ n = m := by
grind [MyInt.natCast_eq, MyInt.eq]
@[grind]
theorem MyInt.eq_0_of_cast_eq_0 (n : Nat) (h : (n : MyInt) = 0) : n = 0 := by
rw [show (0 : MyInt) = ((0 : Nat) : MyInt) by rfl] at h
rwa [natCast_inj] at h
theorem MyInt.pos_iff_gt_0 {a : MyInt} : (∃ (n:Nat), n > 0 ∧ a = n) → a ≠ 0 := by
intro ⟨ w, hw ⟩ h
grind
example {a : MyInt} : (∃ (n:Nat), n > 0 ∧ a = n) → a ≠ 0 := by
grind