English
Similar to 70019, but with a focus on the reverse direction of the equivalence induced by α between cones and their IsLimit structures.
Русский
Повторение идеи 70019: эквивалентость IsLimit через α между конусами и соответствующими ограничениями.
LaTeX
$$$ IsLimit c \\simeq IsLimit d \\text{ via } (postcompose \\alpha.hom) \\text{ and } w $$$
Lean4
/-- Constructing an equivalence `IsLimit c ≃ IsLimit d` from a natural isomorphism
between the underlying functors, and then an isomorphism between `c` transported along this and `d`.
-/
def equivOfNatIsoOfIso {F G : J ⥤ C} (α : F ≅ G) (c : Cone F) (d : Cone G) (w : (Cones.postcompose α.hom).obj c ≅ d) :
IsLimit c ≃ IsLimit d :=
(postcomposeHomEquiv α _).symm.trans (equivIsoLimit w)