proposition: Lemma nth_polyCons a p k : nth (polyCons a p) k = if k is k'.+1 then nth p k' else a.
proof: Proof. by case: k. 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