Map · 54
general topology
MSC 54 · General topology
22,030 declarations (18,559 theorems, 3,471 definitions) across 456 files. 7 of the 30 famous theorems listed for this area are in Mathlib (23%), 8 in some Lean library. 14 open conjectures here are stated in Lean.
Files are assigned to areas by a language model reading each file's documentation. Report a file that is in the wrong area.
Subareas7
- 54A Generalities in topology 5,834
- 54E Topological spaces with richer structures 5,570
- 54C Maps and general types of topological spaces defined by maps 3,764
- 54D Fairly general properties of topological spaces 3,476
- 54B Basic constructions in general topology 1,267
- 54H Connections of general topology with other structures, applications 1,097
- 54F Special properties of topological spaces 1,022
Famous theorems7 of 30
From the 1000+ theorems project, which classifies each theorem by MSC area.
Not yet in Mathlib · 23
In Mathlib · 7
- Baire category theoremdense_sInter_of_isOpen
- Banach fixed-point theoremContractingWith.exists_fixedPoint
- Lebesgue's decomposition theoremMeasureTheory.Measure.haveLebesgueDecomposition_of_sigmaFinite
- Lebesgue's density theoremBesicovitch.ae_tendsto_measure_inter_div
- Metrization theoremsTopologicalSpace.metrizableSpace_of_t3_secondCountable
- Tietze extension theoremBoundedContinuousFunction.exists_extension_norm_eq_of_isClosedEmbedding
- Tychonoff's theoremisCompact_pi_infinite
From the 100 theorems list1
Open conjectures stated in Lean14
Statements without proofs, collected by the Formal Conjectures project.
- BingBorsuk.bing_borsuk_conjectureWikipedia
- Mathoverflow235893.mathoverflow_235893MathOverflow
- PoincareConjecture.poincare_conjecture.variants.smooth_dimension_fourMillennium Prize Problems
- PoincareConjecture.poincare_conjecture.variants.smooth_other_casesMillennium Prize Problems
Undergraduate topics still missing3 of 44
From Mathlib's own undergraduate checklist.
Topology · 3 of 44
- Normed vector spaces on $\R$ and $\C$ › equivalent norms
- Hilbert spaces › example, classical Hilbert bases of orthogonal polynomials
- Hilbert spaces › $H^1_0([0,1])$ and its application to the one-dimensional Dirichlet problem
Structures defined here24
Typeclasses defined in this area's files, most assumed first.
- TopologicalSpace 46,720
- CompleteSpace 3,087
- UniformSpace 2,919
- PseudoEMetricSpace 2,262
- PseudoMetricSpace 2,041
- MetricSpace 1,981
- T2Space 1,565
- OrderTopology 1,541
- ContinuousConstSMul 1,450
- CompactSpace 748
- SecondCountableTopology 718
- Filter.NeBot 506
- IsBoundedSMul 460
- OrderClosedTopology 455
- LocallyCompactSpace 372
- StandardBorelSpace 360
- DiscreteTopology 359
- EMetricSpace 334
- TopologicalSpace.PseudoMetrizableSpace 295
- T1Space 283
- Filter.IsCountablyGenerated 234
- Bornology 225
- IsUltrametricDist 199
- T0Space 197
Files456
Largest first. The code after each file is its assigned subarea.
- Mathlib.Order.Filter.Pointwise
Pointwise operations on filters
54A · 358
- Mathlib.Order.Filter.Basic
Theory of filters on sets
54A · 310
- Mathlib.Topology.Constructions
Constructions of new topological spaces from old ones
54B · 283
- Mathlib.Topology.MetricSpace.Pseudo.Defs
Pseudo-metric spaces
54E · 271
- Mathlib.Topology.Sets.Compacts
Compact sets
54D · 257
- Mathlib.Logic.Equiv.PartialEquiv
Partial equivalences
54A · 245
- Mathlib.Topology.EMetricSpace.Defs
Extended metric spaces
54E · 236
- Mathlib.Topology.Order
Ordering on topologies and (co)induced topologies
54A · 228
- Mathlib.Topology.Semicontinuity.Defs
Semicontinuous maps
54C · 214
- Mathlib.Topology.Separation.Basic
Separation properties of topological spaces
54D · 212
- Mathlib.Order.Filter.Map
Theorems about map and comap on filters.
54A · 203
- Mathlib.Topology.Constructions.SumProd
Disjoint unions and products of topological spaces
54B · 203