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Theorems · Theorem · general topology

countable_setOfPred_covBy_right

∀ {α : Type u} [inst : TopologicalSpace α] [inst_1 : LinearOrder α] [OrderTopology α] [SecondCountableTopology α],
  {x | ∃ y, x ⋖ y}.Countable

The set of points which are isolated on the right is countable when the space is second-countable.

Defined in
Mathlib.Topology.Order.Basic
Cited by
3 results in Mathlib
Foundations
Depth 90 from the axioms · uses propext, Classical.choice, Quot.sound
Assumes
TopologicalSpaceLinearOrderOrderTopologySecondCountableTopology

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