This non-implication,
Form 18 \( \not \Rightarrow \)
Form 8,
whose code is 6,
is constructed around a proven non-implication as follows:
Note: This non-implication is actually a code 4, as this non-implication satisfies the
transferability criterion. Click
Transfer details for all the details)
Hypothesis | Statement |
---|---|
Form 379 | <p> \(PKW(\infty,\infty,\infty)\): For every infinite family \(X\) of sets each of which has at least two elements, there is an infinite subfamily \(Y\) of \(X\) and a function \(f\) such that for all \(y\in Y\), \(f(y)\) is a non-empty proper subset of \(y\). </p> |
Conclusion | Statement |
---|---|
Form 355 | <p> \(KW(\aleph_0,\infty)\), <strong>The Kinna-Wagner Selection Principle</strong> for a denumerable family of sets: For every denumerable set \(M\) there is a function \(f\) such that for all \(A\in M\), if \(|A| > 1\) then \(\emptyset\neq f(A)\subsetneq A\). </p> |
The conclusion Form 18 \( \not \Rightarrow \) Form 8 then follows.
Finally, the
List of models where hypothesis is true and the conclusion is false:
Name | Statement |
---|---|
\(\cal N3\) Mostowski's Linearly Ordered Model | \(A\) is countably infinite;\(\precsim\) is a dense linear ordering on \(A\) without first or lastelements (\((A,\precsim) \cong (\Bbb Q,\le)\)); \(\cal G\) is the group of allorder automorphisms on \((A,\precsim)\); and \(S\) is the set of all finitesubsets of \(A\) |