We have the following indirect implication of form equivalence classes:
			
| Implication | Reference | 
|---|---|
| 112 \(\Rightarrow\) 90 | Equivalents of the Axiom of Choice II, Rubin/Rubin, 1985, page 79 | 
| 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 | 
|---|---|
| 112: | \(MC(\infty,LO)\): For every family \(X\) of non-empty sets each of which can be linearly ordered there is a function \(f\) such that for all \(y\in X\), \(f(y)\) is a non-empty finite subset of \(y\). | 
| 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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