proposition: Lemma size_basis n d: size (sbasis n.+1 d) = 'C(d + n, d).
proof: Proof. by rewrite size_map -cardE; apply/card_sorted_tuples. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq path) mathcomp(choice fintype tuple finfun bigop finset binomial) mathcomp(order fingroup perm ssralg zmodp poly ssrint) mathcomp(matrix vector) mathcomp(bigenough) ssrcomplements freeg