We have the following indirect implication of form equivalence classes:
			
| Implication | Reference | 
|---|---|
| 430-p \(\Rightarrow\) 67 | clear | 
| 67 \(\Rightarrow\) 89 | On cardinals and their successors, Jech,  T. 1966a, Bull. Acad. Polon. Sci. S'er. Sci. Math. Astronom. Phys. | 
| 89 \(\Rightarrow\) 90 | The Axiom of Choice, Jech, 1973b, page 133 | 
| 90 \(\Rightarrow\) 91 | The Axiom of Choice, Jech, 1973b, page 133 | 
| 91 \(\Rightarrow\) 79 | clear | 
| 79 \(\Rightarrow\) 289 | clear | 
Here are the links and statements of the form equivalence classes referenced above:
| Howard-Rubin Number | Statement | 
|---|---|
| 430-p: | (Where \(p\) is a prime) \(AL21\)\((p)\): Every vector space over \(\mathbb Z_p\) has the property that for every subspace \(S\) of \(V\), there is a subspace \(S'\) of \(V\) such that \(S \cap S' = \{ 0 \}\) and \(S \cup S'\) generates \(V\) in other words such that \(V = S \oplus S'\). Rubin, H./Rubin, J [1985], p.119, AL21. | 
| 67: | \(MC(\infty,\infty)\) \((MC)\), The Axiom of Multiple Choice: For every set \(M\) of non-empty sets there is a function \(f\) such that \((\forall x\in M)(\emptyset\neq f(x)\subseteq x\) and \(f(x)\) is finite). | 
| 89: | Antichain Principle: Every partially ordered set has a maximal antichain. Jech [1973b], p 133. | 
| 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. | 
| 289: | If \(S\) is a set of subsets of a countable set and \(S\) is closed under chain unions, then \(S\) has a \(\subseteq\)-maximal element. | 
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