Filter.mem_iff_ultrafilter

∀ {α : Type u} {f : Filter α} {s : Set α}, s ∈ f ↔ ∀ (g : Ultrafilter α), ↑g ≤ f → s ∈ g

Defined in: Mathlib.Order.Filter.Ultrafilter.Defs
Cited by: 1 results in Mathlib
Foundations: Depth 76 from the axioms · uses propext, Classical.choice, Quot.sound

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