Mathlib Map

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
Assumes
TopologicalSpaceLinearOrderOrderTopologyDenselyOrderedTopologicalSpace.SeparableSpace

Around this declaration

Dashed lines are statement dependencies; solid lines are citations in proofs.

Cites16

Mathlib declarations this one mentions in its statement or cites explicitly in its proof. Plumbing is filtered out.

Cited by0

Results whose statement or proof uses this declaration.

Nothing cites this yet.