proposition: Lemma cvgNP f a : - f @ F --> - a <-> f @ F --> a.
proof: Proof. by split=> /cvgN//; rewrite !opprK. Qed.
imports: HB(structures) mathcomp(all_ssreflect ssralg ssrint ssrnum finmap matrix) mathcomp(rat interval zmodp vector fieldext falgebra) mathcomp(mathcomp_extra boolp classical_sets functions) mathcomp(cardinality set_interval Rstruct) ereal reals signed topology prodnormedzmodule