This non-implication,
Form 0 \( \not \Rightarrow \)
Form 405,
whose code is 4, is constructed around a proven non-implication as follows:
| Hypothesis | Statement |
|---|---|
| Form 217 | <p> Every infinite partially ordered set has either an infinite chain or an infinite antichain. </p> |
| Conclusion | Statement |
|---|---|
| Form 390 | <p> Every infinite set can be partitioned either into two infinite sets or infinitely many sets, each of which has at least two elements. <a href="/excerpts/Ash-1981-1">Ash [1983]</a>. </p> |
The conclusion Form 0 \( \not \Rightarrow \) Form 405 then follows.
Finally, the
List of models where hypothesis is true and the conclusion is false:
| Name | Statement |
|---|---|
| \(\cal N1\) The Basic Fraenkel Model | The set of atoms, \(A\) is denumerable; \(\cal G\) is the group of all permutations on \(A\); and \(S\) isthe set of all finite subsets of \(A\) |