fact: Definition weq_cancel_left_ax {C : category} (W : morphism_class C) : UU := ∀ (x y z : C) (f : x --> y) (g : y --> z), (W _ _) f ⇒ (W _ _) (f · g) ⇒ (W _ _) g.
imports: UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Prelude UniMath.ModelCategories.MorphismClass