English
In the reflexive setting, equality of Prefunctors implies equality of their hom maps as above.
Русский
В области рефлексивности, равенство префункторов порождает равенство их гомоморфизмов отображения.
LaTeX
$$$e:\\ F=G \\Rightarrow Q\\uarr{hom}(F.map f) = G.map f$$$
Lean4
/-- An equality of prefunctors gives an equality on homs. -/
theorem congr_hom {U V : Type*} [Quiver U] [Quiver V] {F G : U ⥤q V} (e : F = G) {X Y : U} (f : X ⟶ Y) :
Quiver.homOfEq (F.map f) (congr_obj e X) (congr_obj e Y) = G.map f :=
by
subst e
simp