Lemma apCDRmult : ∏ x x' y y' : X, x * y ≠ x' * y' → x ≠ x' ∨ y ≠ y'. Proof. exact (isapbinop_op2 (X := ConstructiveDivisionRig_apsetwith2binop X)). Qed.
Require Import UniMath.MoreFoundations.Tactics.