∀ {J : Type u_4} {C : Type u_3} [inst : CategoryTheory.Category.{u_2, u_3} C]
  [inst_1 : CategoryTheory.Limits.HasZeroMorphisms C] {K : Type u_1} {f : J → C} (c : CategoryTheory.Limits.Bicone f)
  (g : K ≃ J) (j : CategoryTheory.Discrete K),
  CategoryTheory.CategoryStruct.comp ((c.whisker g).toCocone.ι.app j)
      (CategoryTheory.Iso.refl (c.whisker g).toCocone.pt).hom =
    ((CategoryTheory.Limits.Cocones.precompose (CategoryTheory.Discrete.functorComp f ⇑g).hom).obj
            (CategoryTheory.Limits.Cocone.whisker (CategoryTheory.Discrete.functor (CategoryTheory.Discrete.mk ∘ ⇑g))
              c.toCocone)).ι.app
      j