∀ {B : Type u_5} [inst : CategoryTheory.Bicategory B] {C : Type u_3} [inst_1 : CategoryTheory.Bicategory C]
  (F : CategoryTheory.StrictlyUnitaryLaxFunctor B C) (x : B),
  CategoryTheory.CategoryStruct.comp (F.mapId x) (CategoryTheory.eqToHom ⋯) =
    CategoryTheory.CategoryStruct.id (CategoryTheory.CategoryStruct.id (F.obj x))