proposition: Lemma odivr0 a : a != 0 -> a %/? 0 = None.
proof: Proof. by case: odivrP=> // x; rewrite mulr0=> ->; 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