English
From an isomorphism i: X ≅ Y in MonCat between MonCat objects, construct a MulEquiv X ≃* Y between their carriers.
Русский
Изоморфизм i: X ≅ Y в MonCat даёт MulEquiv между каррирами X и Y.
LaTeX
$$$\text{Given } i: X \cong Y,\; X \equiv_* Y.$$$
Lean4
/-- Build a `MulEquiv` from an isomorphism in the category `MonCat`. -/
@[to_additive addMonCatIsoToAddEquiv /-- Build an `AddEquiv` from an isomorphism in the category
`AddMonCat`. -/
]
def monCatIsoToMulEquiv {X Y : MonCat} (i : X ≅ Y) : X ≃* Y :=
MonoidHom.toMulEquiv i.hom.hom i.inv.hom (by ext; simp) (by ext; simp)