∀ {B : Type u₁} [inst : CategoryTheory.Bicategory B] (b : B) (C : Type u₂) [inst_1 : CategoryTheory.Bicategory C]
  {a b_1 c : C} (f : a ⟶ b_1) (g : b_1 ⟶ c),
  ((CategoryTheory.Bicategory.Prod.sectR b C).mapComp f g).hom =
    CategoryTheory.Prod.mkHom (CategoryTheory.Bicategory.rightUnitor (CategoryTheory.CategoryStruct.id b)).inv
      (CategoryTheory.CategoryStruct.id (CategoryTheory.CategoryStruct.comp f g))