proposition: Lemma pos_mult_rev_r x y : 0 < x * y -> 0 < x -> 0 < y.
proof: Proof. intros. apply pos_mult_rev_l with x. - rewrite (commutativity (f:=mult));trivial. - trivial. Qed.
imports: HoTT.Classes.theory.apartness HoTT.Classes.interfaces.abstract_algebra HoTT.Classes.interfaces.orders HoTT.Classes.theory.rings HoTT.Classes.orders.orders HoTT.Classes.orders.maps