fact: Fixpoint inject n m (p : {ipoly R[n]}) : {ipoly R[m + n]} := if m is m'.+1 return {ipoly R[m + n]} then (inject m' p)%:P else p.
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