proposition: Lemma isKernel_paths {x y z : C} (f : x --> y) (g : y --> z) (H H' : f · g = ZeroArrow Z x z) (isK : isKernel f g H) : isKernel f g H'.
proof: Proof. assert (e : H = H') by apply hs. induction e. exact isK. Qed.
imports: UniMath.Foundations.PartD UniMath.Foundations.Propositions UniMath.Foundations.Sets UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Isos UniMath.CategoryTheory.Monics UniMath.CategoryTheory.Limits.Equalizers UniMath.CategoryTheory.Limits.Zero