English
For any EquivLike structure e and any b, applying e to inv e b yields b.
Русский
Для любой структуры EquivLike применение e к inv e b даёт b.
LaTeX
$$$e(\text{inv}(e,b)) = b$$$
Lean4
/-- This lemma is only supposed to be used in the generic context, when working with instances
of classes extending `EquivLike`.
For concrete isomorphism types such as `Equiv`, you should use `Equiv.apply_symm_apply`
or its equivalent.
TODO: define a generic form of `Equiv.symm`. -/
@[simp]
theorem apply_inv_apply (e : E) (b : β) : e (inv e b) = b :=
right_inv _ _