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Ultrafilter
An ultrafilter on a nonempty set
1.
2. If
3. If
4. For any subset
An ultrafilter See alsoCofinite Filter, Filter, Measurable Cardinal, Norm UltrapowerThis entry contributed by Viktor Bengtsson Explore with Wolfram|Alpha
More things to try: Cite this as:Weisstein, Eric W., with contributions by Viktor Bengtsson. "Ultrafilter." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/Ultrafilter.html Subject classifications |
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