We have the following indirect implication of form equivalence classes:
| Implication | Reference |
|---|---|
| 202 \(\Rightarrow\) 40 | clear |
| 40 \(\Rightarrow\) 231 |
Abzählbarkeit und Wohlordenbarkeit, Felgner, U. 1974, Comment. Math. Helv. |
| 231 \(\Rightarrow\) 294 | clear |
Here are the links and statements of the form equivalence classes referenced above:
| Howard-Rubin Number | Statement |
|---|---|
| 202: | \(C(LO,\infty)\): Every linearly ordered family of non-empty sets has a choice function. |
| 40: | \(C(WO,\infty)\): Every well orderable set of non-empty sets has a choice function. Moore, G. [1982], p 325. |
| 231: | \(UT(WO,WO,WO)\): The union of a well ordered collection of well orderable sets is well orderable. |
| 294: | Every linearly ordered \(W\)-set is well orderable. |
Comment: