English
For a cone morphism f: c ⟶ c' and a functor G: C ⥤ D, and any j in J, the relation G.map f.hom followed by G.map (c'.π.app j) equals G.map (c.π.app j).
Русский
Для конусного мороморфизма f: c ⟶ c' и функторa G: C ⥤ D и любого j в J, выполняется G.map f.hom ≫ G.map (c'.π.app j) = G.map (c.π.app j).
LaTeX
$$G.map f.hom ≫ G.map (c'.π.app j) = G.map (c.π.app j)$$
Lean4
@[reassoc (attr := simp)]
theorem map_w {c c' : Cone F} (f : c ⟶ c') (G : C ⥤ D) (j : J) : G.map f.hom ≫ G.map (c'.π.app j) = G.map (c.π.app j) :=
by simp only [← map_comp, ConeMorphism.w]