This non-implication,
Form 191 \( \not \Rightarrow \)
Form 239,
whose code is 4, is constructed around a proven non-implication as follows:
Hypothesis | Statement |
---|---|
Form 191 | <p> \(SVC\): There is a set \(S\) such that for every set \(a\), there is an ordinal \(\alpha\) and a function from \(S\times\alpha\) onto \(a\). </p> |
Conclusion | Statement |
---|---|
Form 18 | <p> \(PUT(\aleph_{0},2,\aleph_{0})\): The union of a denumerable family of pairwise disjoint pairs has a denumerable subset. </p> |
The conclusion Form 191 \( \not \Rightarrow \) Form 239 then follows.
Finally, the
List of models where hypothesis is true and the conclusion is false:
Name | Statement |
---|---|
\(\cal M7\) Cohen's Second Model | There are two denumerable subsets\(U=\{U_i:i\in\omega\}\) and \(V=\{V_i:i\in\omega\}\) of \(\cal P({\Bbb R})\)(neither of which is in the model) such that for each \(i\in\omega\), \(U_i\)and \(V_i\) cannot be distinguished in the model |
\(\cal N2\) The Second Fraenkel Model | The set of atoms \(A=\{a_i : i\in\omega\}\) is partitioned into two element sets \(B =\{\{a_{2i},a_{2i+1}\} : i\in\omega\}\). \(\mathcal G \) is the group of all permutations of \( A \) that leave \( B \) pointwise fixed and \( S \) is the set of all finite subsets of \( A \). |