Hypothesis: HR 204:
For every infinite \(X\), there is a function from \(X\) onto \(2X\).
Conclusion: HR 70:
There is a non-trivial ultrafilter on \(\omega\). Jech [1973b], prob 5.24.
List of models where hypothesis is true and the conclusion is false:
| Name | Statement |
|---|---|
| \(\cal M2\) Feferman's model | Add a denumerable number of generic reals to the base model, but do not collect them |
Code: 3
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