proposition: Lemma enum_cast_ord m n (H : n = m): enum 'I_m = [seq cast_ord H i | i <- enum 'I_n].
proof: Proof. by subst m; rewrite /= (eq_map (g := id)) ?map_id // => i; apply: val_inj. Qed.
imports: mathcomp.ssreflect.ssreflect mathcomp(ssreflect ssrbool ssrfun ssrnat eqtype finfun fintype choice seq tuple) mathcomp(finset tuple bigop) tools