fact: Definition isNNegOrNPos (X : I.type) : bool := if I.sign_large X is Xund then false else true.
imports: Coq(ZArith Reals Psatz) mathcomp.ssreflect(ssreflect ssrbool ssrfun eqtype ssrnat bigop) Coquelicot(Coquelicot) Stdlib MathComp Xreal Interval Taylor