This non-implication,
Form 0 \( \not \Rightarrow \)
Form 175,
whose code is 4, is constructed around a proven non-implication as follows:
Hypothesis | Statement |
---|---|
Form 0 | \(0 = 0\). |
Conclusion | Statement |
---|---|
Form 199(\(n\)) | <p> (For \(n\in\omega-\{0,1\}\)) If all \(\varSigma^{1}_{n}\), Dedekind finite subsets of \({}^{\omega }\omega\) are finite, then all \(\varPi^1_n\) Dedekind finite subsets of \({}^{\omega} \omega\) are finite. </p> |
The conclusion Form 0 \( \not \Rightarrow \) Form 175 then follows.
Finally, the
List of models where hypothesis is true and the conclusion is false:
Name | Statement |
---|---|
\(\cal M26\) Kanovei's Model I | Starting with a model of \(ZF + V = L\) and using forcing techniques due to <a href="/excerpts/Jensen-1968">Jensen [1968]</a>, Kanovei constructs a model of \(ZF\) in which there is an infinite Dedekind finite set \(A\) of generic reals that is in the class \(\varPi^1_n\), but there are no infinite Dedekind finite subsets of \(\Bbb R\) in the class \(\varSigma^1_n\), where \(n\in\omega\), \(n\ge 2\) |