We have the following indirect implication of form equivalence classes:

92 \(\Rightarrow\) 34
given by the following sequence of implications, with a reference to its direct proof:

Implication Reference
92 \(\Rightarrow\) 94 clear
94 \(\Rightarrow\) 34 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
92:

\(C(WO,{\Bbb R})\):  Every well ordered family of non-empty subsets of \({\Bbb R}\) has a choice function.

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.

34:

\(\aleph_{1}\) is regular.

Comment:

Back