We have the following indirect implication of form equivalence classes:

129 \(\Rightarrow\) 405
given by the following sequence of implications, with a reference to its direct proof:

Implication Reference
129 \(\Rightarrow\) 4 clear
4 \(\Rightarrow\) 405 clear

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

Howard-Rubin Number Statement
129:

For every infinite set \(A\), \(A\) admits a partition into sets of order type \(\omega^{*} + \omega\). (For every infinite \(A\), there is a set \(\{\langle C_j,<_j \rangle: j\in J\}\) such that \(\{C_j: j\in J\}\) is a partition of \(A\) and for each \(j\in J\), \(<_j\) is an ordering of \(C_j\) of type \(\omega^* + \omega\).)

4:

Every infinite set is the union of some disjoint family of denumerable subsets. (Denumerable means \(\cong \aleph_0\).)

405:

Every infinite set can be partitioned into sets each of which is countable and has at least two elements.

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