We have the following indirect implication of form equivalence classes:

231 \(\Rightarrow\) 18
given by the following sequence of implications, with a reference to its direct proof:

Implication Reference
231 \(\Rightarrow\) 18 clear

Here are the links and statements of the form equivalence classes referenced above:

Howard-Rubin Number Statement
231:

\(UT(WO,WO,WO)\): The union of a well ordered collection of well orderable sets is well orderable.

18:

\(PUT(\aleph_{0},2,\aleph_{0})\):  The union of a denumerable family of pairwise disjoint pairs has a denumerable subset.

Comment:

Back