Theorems · Theorem · general topology
continuousAt_iff_punctured_nhds
∀ {α : Type u_1} {β : Type u_2} [inst : TopologicalSpace α] [inst_1 : TopologicalSpace β] {f : α → β} {a : α},
ContinuousAt f a ↔ Filter.Tendsto f (nhdsWithin a {a}ᶜ) (nhds (f a))- Defined in
- Mathlib.Topology.NhdsWithin
- Cited by
- 4 results in Mathlib
- Foundations
- Depth 66 from the axioms · uses propext, Classical.choice, Quot.sound
Around this declaration
Dashed lines are statement dependencies; solid lines are citations in proofs.
Cites8
Mathlib declarations this one mentions in its statement or cites explicitly in its proof. Plumbing is filtered out.
- Setstatement · cited by 53,352
- TopologicalSpacestatement and proof · cited by 24,529
- nhdsstatement and proof · cited by 5,554
- Filter.Tendstostatement and proof · cited by 3,814
- Compl.complstatement and proof · cited by 2,925
- nhdsWithinstatement and proof · cited by 1,912
- ContinuousAtstatement · cited by 697
- pure_sup_nhdsNEproof · cited by 1
Cited by4
Results whose statement or proof uses this declaration.
- differentiable_riemannZeta₀proof · cited by 5
- Complex.not_continuousAt_Gamma_zeroproof · cited by 2
- Complex.tendsto_self_mul_Gamma_nhds_zeroproof · cited by 2
- AnalyticAt.of_meromorphicOrderAt_posproof · cited by 0