proposition: Lemma adjoin_seq1 V x : <<V & [:: x]>>%VS = <<V; x>>%VS.
proof: Proof. by rewrite adjoin_cons adjoin_nil agenv_id. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq path) mathcomp(choice fintype div tuple finfun bigop ssralg) mathcomp(finalg zmodp matrix vector poly)