proposition: Lemma odivr1 a : a %/? 1 = Some a.
proof: Proof. case: odivrP=> [x|H]; first by rewrite mulr1=> ->. by move: (H a); rewrite mulr1 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