proposition: Lemma ltxi0s s : ([::] < s :> seq T) = (s != [::]).
proof: Proof. by case: s. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat choice seq) mathcomp(path fintype tuple bigop finset div prime finfun) mathcomp(finset)