proposition: Lemma eqd_mul c d a b : a %= c -> b %= d -> a * b %= c * d.
proof: Proof. by rewrite /eqd; do 2!case/andP=> ? ?; rewrite !dvdr_mul. Qed.
imports: HB(structures) Coq(ssreflect ssrfun ssrbool Arith.Wf_nat) mathcomp(eqtype ssrnat div seq path) mathcomp(ssralg fintype perm tuple choice generic_quotient) mathcomp(matrix bigop zmodp mxalgebra poly) stronglydiscrete