We have the following indirect implication of form equivalence classes:
Implication | Reference |
---|---|
152 \(\Rightarrow\) 4 |
Russell's alternative to the axiom of choice, Howard, P. 1992, Z. Math. Logik Grundlagen Math. note-27 note-27 note-27 |
4 \(\Rightarrow\) 405 | clear |
405 \(\Rightarrow\) 75 | clear |
Here are the links and statements of the form equivalence classes referenced above:
Howard-Rubin Number | Statement |
---|---|
152: | \(D_{\aleph_{0}}\): Every non-well-orderable set is the union of a pairwise disjoint, well orderable family of denumerable sets. (See note 27 for \(D_{\kappa}\), \(\kappa\) a well ordered cardinal.) |
4: | Every infinite set is the union of some disjoint family of denumerable subsets. (Denumerable means \(\cong \aleph_0\).) |
405: | Every infinite set can be partitioned into sets each of which is countable and has at least two elements. |
75: | If a set has at least two elements, then it can be partitioned into well orderable subsets, each of which has at least two elements. |
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