proposition: Lemma odivr_mulrK a b : a != 0 -> b * a %/? a = Some b.
proof: Proof. move=> a0; case: odivrP=> [x|H]; first by move/(mulIf a0) ->. by move: (H b); rewrite eqxx. 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