proposition: Lemma npolyXE (i : 'I_n) : 'nX^i = 'X^i :> {poly _}.
proof: Proof. by rewrite tnth_map tnth_ord_tuple npolypK // size_polyXn. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice fintype tuple) mathcomp(bigop binomial finset finfun ssralg countalg finalg poly polydiv) mathcomp(perm fingroup matrix mxalgebra mxpoly vector countalg)