We have the following indirect implication of form equivalence classes:
			
| Implication | Reference | 
|---|---|
| 286 \(\Rightarrow\) 40 | 								S´eminaire d’Analyse 1992, Morillon, 1991b,  | 
					
| 40 \(\Rightarrow\) 39 | clear | 
| 39 \(\Rightarrow\) 8 | clear | 
| 8 \(\Rightarrow\) 16 | clear | 
| 16 \(\Rightarrow\) 6 | 
							 	L’axiome de M. Zermelo et son rˆole dans la th´eorie des ensembles et l’analyse, Sierpi'nski,  W. 1918, Bull. Int. Acad. Sci. Cracovie Cl. Math. Nat.  | 
					
| 6 \(\Rightarrow\) 5 | 
							 	L’axiome de M. Zermelo et son rˆole dans la th´eorie des ensembles et l’analyse, Sierpi'nski,  W. 1918, Bull. Int. Acad. Sci. Cracovie Cl. Math. Nat.  | 
					
| 5 \(\Rightarrow\) 38 | 
							 	Non-constructive properties of the real numbers, Howard,  P. 2001, Math. Logic Quart.  | 
					
| 38 \(\Rightarrow\) 108 | clear | 
Here are the links and statements of the form equivalence classes referenced above:
| Howard-Rubin Number | Statement | 
|---|---|
| 286: | Extended Krein-Milman Theorem: Let K be a quasicompact (sometimes called convex-compact), convex subset of a locally convex topological vector space, then K has an extreme point. H. Rubin/J. Rubin [1985], p. 177-178.  | 
					
| 40: | \(C(WO,\infty)\): Every well orderable set of non-empty sets has a choice function. Moore, G. [1982], p 325.  | 
					
| 39: | \(C(\aleph_{1},\infty)\): Every set \(A\) of non-empty sets such that \(\vert A\vert = \aleph_{1}\) has a choice function. Moore, G. [1982], p. 202.  | 
					
| 8: | \(C(\aleph_{0},\infty)\):  | 
					
| 16: | \(C(\aleph_{0},\le 2^{\aleph_{0}})\): Every denumerable collection of non-empty sets each with power \(\le 2^{\aleph_{0}}\) has a choice function.  | 
					
| 6: | \(UT(\aleph_0,\aleph_0,\aleph_0,\Bbb R)\): The union of a denumerable family of denumerable subsets of \({\Bbb R}\) is denumerable.  | 
					
| 5: | \(C(\aleph_0,\aleph_0,\Bbb R)\): Every denumerable set of non-empty denumerable subsets of \({\Bbb R}\) has a choice function.  | 
					
| 38: | \({\Bbb R}\) is not the union of a countable family of countable sets.  | 
					
| 108: | There is an ordinal \(\alpha\) such that \(2^{\aleph _{\alpha}}\) is not the union of a denumerable set of denumerable sets.  | 
					
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