We have the following indirect implication of form equivalence classes:
| Implication | Reference |
|---|---|
| 133 \(\Rightarrow\) 90 |
Dedekind-Endlichkeit und Wohlordenbarkeit, Brunner, N. 1982a, Monatsh. Math. |
| 90 \(\Rightarrow\) 91 | The Axiom of Choice, Jech, 1973b, page 133 |
| 91 \(\Rightarrow\) 79 | clear |
| 79 \(\Rightarrow\) 203 | clear |
| 203 \(\Rightarrow\) 306 | clear |
Here are the links and statements of the form equivalence classes referenced above:
| Howard-Rubin Number | Statement |
|---|---|
| 133: | Every set is either well orderable or has an infinite amorphous subset. |
| 90: | \(LW\): Every linearly ordered set can be well ordered. Jech [1973b], p 133. |
| 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. |
| 203: | \(C\)(disjoint,\(\subseteq\Bbb R)\): Every partition of \({\cal P}(\omega)\) into non-empty subsets has a choice function. |
| 306: | The set of Vitali equivalence classes is linearly orderable. (Vitali equivalence classes are equivalence classes of the real numbers under the relation \(x\equiv y\leftrightarrow (\exists q\in{\Bbb Q})(x-y = q)\).). |
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