proposition: Lemma coprimer_gdco q p : p != 0 -> coprimer (gdco q p) q.
proof: Proof. by case: gdcoP => [->|//]; rewrite eqxx. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq path) mathcomp(ssralg fintype matrix mxalgebra bigop zmodp perm choice) dvdring mxstructure minor stronglydiscrete coherent edr