This non-implication,
Form 322 \( \not \Rightarrow \)
Form 274,
whose code is 4, is constructed around a proven non-implication as follows:
Hypothesis | Statement |
---|---|
Form 40 | <p> \(C(WO,\infty)\): Every well orderable set of non-empty sets has a choice function. <a href="/books/2">Moore, G. [1982]</a>, p 325. </p> |
Conclusion | Statement |
---|---|
Form 274 | <p> There is a cardinal number \(x\) and an \(n\in\omega\) such that \(\neg(x\) adj\(^n\, x^2)\). (The expression ``\(x\) adj\(^n\, ya\)" means there are cardinals \(z_0,\ldots, z_n\) such that \(z_0 = x\) and \(z_n = y\) and for all \(i,\ 0\le i < n,\ z_i< z_{i+1}\) and if \(z_i < z\le z_{i+1}\), then \(z = z_{i+1}.)\) (Compare with <a href="/form-class-members/howard-rubin-0-a">[0 A]</a>). </p> |
The conclusion Form 322 \( \not \Rightarrow \) Form 274 then follows.
Finally, the
List of models where hypothesis is true and the conclusion is false:
Name | Statement |
---|---|
\(\cal M2\) Feferman's model | Add a denumerable number of generic reals to the base model, but do not collect them |