We have the following indirect implication of form equivalence classes:
Implication | Reference |
---|---|
15 \(\Rightarrow\) 30 | The Axiom of Choice, Jech, 1973b, page 53 problem 4.12 |
30 \(\Rightarrow\) 62 | clear |
62 \(\Rightarrow\) 61 | clear |
61 \(\Rightarrow\) 88 | clear |
88 \(\Rightarrow\) 140 | clear |
Here are the links and statements of the form equivalence classes referenced above:
Howard-Rubin Number | Statement |
---|---|
15: | \(KW(\infty,\infty)\) (KW), The Kinna-Wagner Selection Principle: For every set \(M\) there is a function \(f\) such that for all \(A\in M\), if \(|A|>1\) then \(\emptyset\neq f(A)\subsetneq A\). (See Form 81(\(n\)). |
30: | Ordering Principle: Every set can be linearly ordered. |
62: | \(C(\infty,< \aleph_{0})\): Every set of non-empty finite sets has a choice function. |
61: | \((\forall n\in\omega, n\ge 2\))\((C(\infty,n))\): For each \(n\in\omega\), \(n\ge 2\), every set of \(n\) element sets has a choice function. |
88: | \(C(\infty ,2)\): Every family of pairs has a choice function. |
140: | Let \(\Omega\) be the set of all (undirected) infinite cycles of reals (Graphs whose vertices are real numbers, connected, no loops and each vertex adjacent to exactly two others). Then there is a function \(f\) on \(\Omega \) such that for all \(s\in\Omega\), \(f(s)\) is a direction along \(s\). |
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