This non-implication,
Form 165 \( \not \Rightarrow \)
Form 352,
whose code is 4, is constructed around a proven non-implication as follows:
Hypothesis | Statement |
---|---|
Form 165 | <p> \(C(WO,WO)\): Every well ordered family of non-empty, well orderable sets has a choice function. </p> |
Conclusion | Statement |
---|---|
Form 31 | <p>\(UT(\aleph_{0},\aleph_{0},\aleph_{0})\): <strong>The countable union theorem:</strong> The union of a denumerable set of denumerable sets is denumerable. </p> |
The conclusion Form 165 \( \not \Rightarrow \) Form 352 then follows.
Finally, the
List of models where hypothesis is true and the conclusion is false:
Name | Statement |
---|---|
\(\cal M12(\aleph)\) Truss' Model I | This is a variation of Solovay's model, <a href="/models/Solovay-1">\(\cal M5(\aleph)\)</a> in which \(\aleph\) is singular |
\(\cal M20\) Felgner's Model I | Let \(\cal M\) be a model of \(ZF + V = L\). Felgner defines forcing conditions that force \(\aleph_{\omega}\) in \(\cal M\) to be \(\aleph_1\) |