We have the following indirect implication of form equivalence classes:
| Implication | Reference |
|---|---|
| 79 \(\Rightarrow\) 94 | clear |
| 94 \(\Rightarrow\) 34 |
Non-constructive properties of the real numbers, Howard, P. 2001, Math. Logic Quart. |
| 34 \(\Rightarrow\) 104 | clear |
| 104 \(\Rightarrow\) 182 | clear |
Here are the links and statements of the form equivalence classes referenced above:
| Howard-Rubin Number | Statement |
|---|---|
| 79: | \({\Bbb R}\) can be well ordered. Hilbert [1900], p 263. |
| 94: | \(C(\aleph_{0},\infty,{\Bbb R})\): Every denumerable family of non-empty sets of reals has a choice function. Jech [1973b], p 148 prob 10.1. |
| 34: | \(\aleph_{1}\) is regular. |
| 104: | There is a regular uncountable aleph. Jech [1966b], p 165 prob 11.26. |
| 182: | There is an aleph whose cofinality is greater than \(\aleph_{0}\). |
Comment: