proposition: Lemma cut_minus_ring_minus (x y : R) : y ≤ x → x ∸ y = x - y.
proof: Proof. intros. apply (right_cancellation (+) y). ring_simplify. now auto. Qed.
imports: Coq.setoid_ring.Ring MathClasses.interfaces.abstract_algebra MathClasses.interfaces.additional_operations MathClasses.interfaces.orders MathClasses.orders.minmax