Lemma CDRplus_apcompat_l : ∏ x y z : X, y + x ≠ z + x → y ≠ z. Proof. intros x y z. exact (islapbinop_op1 (X := ConstructiveDivisionRig_apsetwith2binop X) _ _ _). Qed.
Require Import UniMath.MoreFoundations.Tactics.