proposition: Lemma pseries_diffsN (f : nat -> R) : pseries_diffs (- f) = -(pseries_diffs f).
proof: Proof. by apply/funext => i; rewrite /pseries_diffs /= -mulrN. Qed.
imports: mathcomp(all_ssreflect ssralg ssrint ssrnum matrix) mathcomp(interval rat) mathcomp(boolp classical_sets functions) mathcomp(mathcomp_extra) reals ereal signed topology normedtype landau sequences derive realfun itv convex