This non-implication,
Form 390 \( \not \Rightarrow \)
Form 4,
whose code is 4, is constructed around a proven non-implication as follows:
| Hypothesis | Statement |
|---|---|
| Form 64 | <p> \(E(I,Ia)\) There are no amorphous sets. (Equivalently, every infinite set is the union of two disjoint infinite sets.) </p> |
| Conclusion | Statement |
|---|---|
| Form 83 | <p> \(E(I,II)\) <a href="/articles/Howard-Yorke-1989">Howard/Yorke [1989]</a>: \(T\)-finite is equivalent to finite. </p> |
The conclusion Form 390 \( \not \Rightarrow \) Form 4 then follows.
Finally, the
List of models where hypothesis is true and the conclusion is false:
| Name | Statement |
|---|---|
| \(\cal N4\) The Mathias/Pincus Model I | \(A\) is countably infinite;\(\precsim\) is a universal homogeneous partial ordering on \(A\) (See<a href="/articles/Jech-1973b">Jech [1973b]</a> p 101 for definitions.); \(\cal G\) is the group ofall order automorphisms on \((A,\precsim)\); and \(S\) is the set of allfinite subsets of \(A\) |