proposition: Lemma subseq_take (s : seq T) m : subseq (take m s) s.
proof: Proof. by elim: s m => // a l ih [] //= n; rewrite eqxx. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq path) mathcomp(ssralg fintype finfun perm matrix bigop zmodp mxalgebra) mathcomp(choice poly polydiv mxpoly binomial)