lean2/tests/lean/tactic_id_bug.lean

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import algebra.function
open function
structure bijection (A : Type) :=
(func finv : A → A)
(linv : finv ∘ func = id)
(rinv : func ∘ finv = id)
attribute bijection.func [coercion]
namespace bijection
variable {A : Type}
protected theorem eq {f g : bijection A}
(func_eq : func f = func g) (finv_eq : finv f = finv g) : f = g :=
begin
revert finv_eq,
revert func_eq,
cases g with [gfunc, gfinv, glinv, grinv],
cases f with [func, finv, linv, rinv],
state,
esimp,
intros [func_eq, finv_eq],
revert grinv, revert glinv, revert rinv, revert linv,
rewrite [func_eq, finv_eq],
intros [H1, H2, H3, H4],
apply rfl
end
end bijection