We have the following indirect implication of form equivalence classes:
Implication | Reference |
---|---|
260 \(\Rightarrow\) 40 |
Variations of Zorn's lemma, principles of cofinality, and Hausdorff's maximal principle, Part I and II, Harper, J. 1976, Notre Dame J. Formal Logic |
40 \(\Rightarrow\) 39 | clear |
39 \(\Rightarrow\) 8 | clear |
8 \(\Rightarrow\) 27 | clear |
27 \(\Rightarrow\) 31 | clear |
31 \(\Rightarrow\) 34 | clear |
34 \(\Rightarrow\) 104 | clear |
104 \(\Rightarrow\) 182 | clear |
Here are the links and statements of the form equivalence classes referenced above:
Howard-Rubin Number | Statement |
---|---|
260: | \(Z(TR\&C,P)\): If \((X,R)\) is a transitive and connected relation in which every partially ordered subset has an upper bound, then \((X,R)\) has a maximal element. |
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: | \(C(\aleph_{0},\infty)\): |
27: | \((\forall \alpha)( UT(\aleph_{0},\aleph_{\alpha}, \aleph_{\alpha}))\): The union of denumerably many sets each of power \(\aleph_{\alpha }\) has power \(\aleph_{\alpha}\). Moore, G. [1982], p 36. |
31: | \(UT(\aleph_{0},\aleph_{0},\aleph_{0})\): The countable union theorem: The union of a denumerable set of denumerable sets is denumerable. |
34: | \(\aleph_{1}\) is regular. |
104: | There is a regular uncountable aleph. Jech [1966b], p 165 prob 11.26. |
182: | There is an aleph whose cofinality is greater than \(\aleph_{0}\). |
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