fact: Definition T_atan x := let q1 := P.one in let J := C.atan u x in let s := [:: J] in let F q n := let q2nX := P.mul_mixed u (C.from_nat u ((n.-1).*2)) (P.lift 1 q) in let q' := P.deriv u q in P.div_mixed_r u (P.sub u (P.add u q' (P.lift 2 q')) q2nX) (C.from_nat u n) in let G q n := C.div u (P.horner u q x) (C.power_int u (C.add u C.one (C.sqr u x)) (Z_of_nat n)) in P.grec1 F G q1 s.
imports: Coq(ZArith Reals) Flocq(Raux) mathcomp.ssreflect(ssreflect ssrfun ssrbool eqtype ssrnat seq fintype bigop) Interval Datatypes Basic_rec