proposition: Lemma lift_correct n pi p : pi >:: p -> lift n pi >:: PolR.lift n p.
proof: Proof. move=> Hp k; rewrite /nth /PolR.nth. by apply: (ncons_correct (Rel := fun v t => t >: v)); first exact: J.zero_correct. Qed.
imports: Coq(ZArith Reals) Coquelicot(Coquelicot) mathcomp.ssreflect(ssreflect ssrfun ssrbool eqtype ssrnat seq fintype bigop) Flocq(Core) Stdlib MathComp Interval Xreal Basic_rec