proposition: Lemma divp_pmul2r d p q : d != 0 -> p != 0 -> q * d %/ (p * d) = q %/ p.
proof: Proof. by move=> dn0 qn0; rewrite -!(mulrC d) divp_pmul2l. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype bigop ssralg poly)