proposition: Lemma val_unitX n x : val (x ^+ n : unit_of)%g = val x ^+ n.
proof: Proof. by case: n; last by elim=> //= n ->. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype finset fingroup morphism perm action) mathcomp(ssralg countalg)