fact: Definition T_cos x := P.rec2 (cos_rec u) (C.cos u x) (C.opp (C.sin u x)).
imports: Coq(ZArith Reals) Flocq(Raux) mathcomp.ssreflect(ssreflect ssrfun ssrbool eqtype ssrnat seq fintype bigop) Interval Datatypes Basic_rec