We have the following indirect implication of form equivalence classes:
Implication | Reference |
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68 \(\Rightarrow\) 62 |
Subgroups of a free group and the axiom of choice, Howard, P. 1985, J. Symbolic Logic |
Here are the links and statements of the form equivalence classes referenced above:
Howard-Rubin Number | Statement |
---|---|
68: | Nielsen-Schreier Theorem: Every subgroup of a free group is free. Jech [1973b], p 12. |
62: | \(C(\infty,< \aleph_{0})\): Every set of non-empty finite sets has a choice function. |
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