This non-implication,
Form 280 \( \not \Rightarrow \)
Form 222,
whose code is 4, is constructed around a proven non-implication as follows:
| Hypothesis | Statement |
|---|---|
| Form 142 | <p> \(\neg PB\): There is a set of reals without the property of Baire. <a href="/books/8">Jech [1973b]</a>, p. 7. </p> |
| Conclusion | Statement |
|---|---|
| Form 222 | <p> There is a non-principal measure on \(\cal P(\omega)\). </p> |
The conclusion Form 280 \( \not \Rightarrow \) Form 222 then follows.
Finally, the
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 |