We have the following indirect implication of form equivalence classes:
| Implication | Reference |
|---|---|
| 264 \(\Rightarrow\) 202 |
Variations of Zorn's lemma, principles of cofinality, and Hausdorff's maximal principle, Part I and II, Harper, J. 1976, Notre Dame J. Formal Logic |
| 202 \(\Rightarrow\) 91 | note-75 |
| 91 \(\Rightarrow\) 79 | clear |
| 79 \(\Rightarrow\) 139 |
Here are the links and statements of the form equivalence classes referenced above:
| Howard-Rubin Number | Statement |
|---|---|
| 264: | \(H(C,P)\): Every connected relation \((X,R)\) contains a \(\subseteq\)-maximal partially ordered set. |
| 202: | \(C(LO,\infty)\): Every linearly ordered family of non-empty sets has a choice function. |
| 91: | \(PW\): The power set of a well ordered set can be well ordered. |
| 79: | \({\Bbb R}\) can be well ordered. Hilbert [1900], p 263. |
| 139: | Using the discrete topology on 2, \(2^{\cal P(\omega)}\) is compact. |
Comment: