proposition: Lemma fmodKcond x : val (fmod x) = if x \in A then x else 1%g.
proof: Proof. by rewrite /= /fmval /= val_insubd. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq path) mathcomp(div choice fintype bigop ssralg finset fingroup) mathcomp(morphism perm finalg action gproduct commutator) mathcomp(cyclic)