proposition: Lemma continuity_ptE (f : R -> R) (x : R) : Ranalysis1.continuity_pt f x <-> {for x, continuous f}.
proof: Proof. exact: continuity_pt_cvg. 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