fact: Definition deriv_loop := foldri (fun a i s => C.mul u a (C.from_nat u i) :: s) [::].
imports: Coq(ZArith Reals) Coquelicot(Coquelicot) mathcomp.ssreflect(ssreflect ssrfun ssrbool eqtype ssrnat seq fintype bigop) Flocq(Core) Stdlib MathComp Interval Xreal Basic_rec