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