proposition: Lemma aimgX (f : ahom aT rT) U n : (f @: (U ^+ n) = f @: U ^+ n)%VS.
proof: Proof. elim: n => [|n IH]; first by rewrite !expv0 aimg1. by rewrite !expvSl aimgM IH. 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)