proposition: Lemma cvg_sub0 f g a : (f - g) @ F --> (0 : V) -> g @ F --> a -> f @ F --> a.
proof: Proof. by move=> Cfg Cg; have := cvgD Cfg Cg; rewrite subrK add0r; apply. 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