We have the following indirect implication of form equivalence classes:

82 \(\Rightarrow\) 64
given by the following sequence of implications, with a reference to its direct proof:

Implication Reference
82 \(\Rightarrow\) 83 Definitions of finite, Howard, P. 1989, Fund. Math.
83 \(\Rightarrow\) 64 The Axiom of Choice, Jech, 1973b, page 52 problem 4.10

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

Howard-Rubin Number Statement
82:

\(E(I,III)\) (Howard/Yorke [1989]): If \(X\) is infinite then \(\cal P(X)\) is Dedekind infinite. (\(X\) is finite \(\Leftrightarrow {\cal P}(X)\) is Dedekind finite.)

83:

\(E(I,II)\) Howard/Yorke [1989]: \(T\)-finite is equivalent to finite.

64:

\(E(I,Ia)\) There are no amorphous sets. (Equivalently, every infinite set is the union of two disjoint infinite sets.)

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