proposition: Lemma continuity_pt_cvg' f x : Ranalysis1.continuity_pt f x <-> f @ x^' --> f x.
proof: Proof. by rewrite continuity_ptE continuous_withinNx. 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