English
Multiplicative equivalences between groups are equivalent to isomorphisms in GrpCat.
Русский
Умножаемые эквиваленты между группами эквивалентны изоморфизмам в GrpCat.
LaTeX
$$$$ \forall X,Y:\mathrm{GrpCat},\; (X \simeq_* Y) \simeq (X \cong Y). $$$$
Lean4
/-- multiplicative equivalences between `Group`s are the same as (isomorphic to) isomorphisms
in `GrpCat` -/
@[to_additive]
def mulEquivIsoGroupIso {X Y : GrpCat.{u}} : X ≃* Y ≅ X ≅ Y
where
hom e := e.toGrpIso
inv i := i.groupIsoToMulEquiv