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Theorems · Theorem · general topology

Dense.inter_of_isOpen_left

∀ {X : Type u} [inst : TopologicalSpace X] {s t : Set X}, Dense s → Dense t → IsOpen s → Dense (s ∩ t)

The intersection of an open dense set with a dense set is a dense set.

Defined in
Mathlib.Topology.Neighborhoods
Cited by
7 results in Mathlib
Foundations
Depth 66 from the axioms · uses propext, Classical.choice, Quot.sound
Assumes
TopologicalSpace

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Cited by7

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