proposition: Lemma dvdr_trans : transitive (@dvdr R).
proof: Proof. move=> b a c; case/dvdrP=> x ->; case/dvdrP=> y ->. by apply/dvdrP; exists (y * x); rewrite mulrA. 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