proposition: Lemma gcdrC a b : gcdr a b %= gcdr b a.
proof: Proof. by rewrite /eqd ?dvdr_gcd ?dvdr_gcdr ?dvdr_gcdl. 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