Theorems · Theorem · general topology
SecondCountableTopology.of_separableSpace_orderTopology
∀ (α : Type u) [inst : TopologicalSpace α] [inst_1 : LinearOrder α] [OrderTopology α] [DenselyOrdered α] [TopologicalSpace.SeparableSpace α], SecondCountableTopology α
Let α be a densely ordered linear order with order topology. If α is a separable space, then
it has second countable topology. Note that the "densely ordered" assumption cannot be dropped, see
[double arrow space](https://topology.pi-base.org/spaces/S000093) for a counterexample.
- Defined in
- Mathlib.Topology.Order.Basic
- Cited by
- 0 results in Mathlib
- Foundations
- Depth 79 from the axioms · uses propext, Classical.choice, Quot.sound
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Cites16
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- Setproof · cited by 53,352
- TopologicalSpacestatement and proof · cited by 24,529
- LinearOrderstatement and proof · cited by 8,572
- Set.imageproof · cited by 5,609
- Set.Ioiproof · cited by 1,463
- OrderTopologystatement and proof · cited by 1,355
- Set.Iioproof · cited by 1,166
- SecondCountableTopologystatement · cited by 750
- Set.Countableproof · cited by 545
- DenselyOrderedstatement and proof · cited by 471
- Denseproof · cited by 359
- TopologicalSpace.SeparableSpacestatement and proof · cited by 109
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