proposition: Lemma pos_mult_rev_l x y : 0 < x * y → 0 < y → 0 < x.
proof: Proof. intros. apply (strictly_order_reflecting (.* y)). now rewrite rings.mult_0_l. Qed.
imports: Coq.setoid_ring.Ring MathClasses.interfaces.abstract_algebra MathClasses.interfaces.orders MathClasses.theory.rings MathClasses.orders.orders MathClasses.orders.maps