We have the following indirect implication of form equivalence classes:
Implication | Reference |
---|---|
328 \(\Rightarrow\) 126 | clear |
126 \(\Rightarrow\) 94 |
Non-constructive properties of the real numbers, Howard, P. 2001, Math. Logic Quart. |
94 \(\Rightarrow\) 6 |
Non-constructive properties of the real numbers, Howard, P. 2001, Math. Logic Quart. |
Here are the links and statements of the form equivalence classes referenced above:
Howard-Rubin Number | Statement |
---|---|
328: | \(MC(WO,\infty)\): For every well ordered set \(X\) such that for all \(x\in X\), \(|x|\ge 1\), there is a function \(f\) such that and for every \(x\in X\), \(f(x)\) is a finite, non-empty subset of \(x\). (See Form 67.) |
126: | \(MC(\aleph_0,\infty)\), Countable axiom of multiple choice: For every denumerable set \(X\) of non-empty sets there is a function \(f\) such that for all \(y\in X\), \(f(y)\) is a non-empty finite subset of \(y\). |
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. |
6: | \(UT(\aleph_0,\aleph_0,\aleph_0,\Bbb R)\): The union of a denumerable family of denumerable subsets of \({\Bbb R}\) is denumerable. |
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