proposition: Lemma is_cvgDrE f g : cvg (f @ F) -> cvg ((f + g) @ F) = cvg (g @ F).
proof: Proof. by rewrite addrC; apply: is_cvgDlE. 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