English
There is a natural bijection between X.nonDegenerate(n) and Y.nonDegenerate(n) induced by an isomorphism e: X ≅ Y.
Русский
Существует натуральная биекция между ненегидными n-симплексами X и Y, индуцируемая изоморфизмом e: X ≅ Y.
LaTeX
$$$$X.nonDegenerate(n) \cong Y.nonDegenerate(n) \text{ via } e,$$$$
Lean4
/-- The bijection on nondegenerate simplices induced by an isomorphism
of simplicial sets. -/
@[simps]
def nonDegenerateEquivOfIso (e : X ≅ Y) {n : ℕ} : X.nonDegenerate n ≃ Y.nonDegenerate n
where
toFun := fun ⟨x, hx⟩ ↦ ⟨e.hom.app _ x, by aesop⟩
invFun := fun ⟨y, hy⟩ ↦ ⟨e.inv.app _ y, by aesop⟩
left_inv _ := by aesop
right_inv _ := by aesop