English
Equivalences between types are in bijection with isomorphisms; this yields an equivalence equivEquivIso: X ≃ Y ≃ (X ≅ Y).
Русский
Эквиваленции между типами соответствуют изоморфизмам; образуется эквивалентность equivEquivIso: X ≃ Y ≃ (X ≅ Y).
LaTeX
$$$ X \\simeq Y \\simeq (X \\cong Y) $$$
Lean4
/-- Equivalences (between types in the same universe) are the same as (equivalent to) isomorphisms
of types. -/
def equivEquivIso {X Y : Type u} : X ≃ Y ≃ (X ≅ Y) :=
equivIsoIso.toEquiv