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