We have the following indirect implication of form equivalence classes:

317 \(\Rightarrow\) 326
given by the following sequence of implications, with a reference to its direct proof:

Implication Reference
317 \(\Rightarrow\) 14 Limitations on the Fraenkel-Mostowski method of independence proofs, Howard, P. 1973, J. Symbolic Logic
14 \(\Rightarrow\) 49 A survey of recent results in set theory, Mathias, A.R.D. 1979, Period. Math. Hungar.
49 \(\Rightarrow\) 326 Logic at Work: Essay Dedicated to the Memory of Helen Rasiowa, Wojtylak, 1999,

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

Howard-Rubin Number Statement
317:

Weak Sikorski Theorem:  If \(B\) is a complete, well orderable Boolean algebra and \(f\) is a homomorphism of the Boolean algebra \(A'\) into \(B\) where \(A'\) is a subalgebra of the Boolean algebra \(A\), then \(f\) can be extended to a homomorphism of \(A\) into \(B\).

14:

BPI: Every Boolean algebra has a prime ideal.

49:

Order Extension Principle: Every partial ordering can be extended to a linear ordering.  Tarski [1924], p 78.

326:

2-SAT:  Restricted Compactness Theorem for Propositional Logic III:   If \(\Sigma\) is a set of formulas in a propositional language such that every finite subset of \(\Sigma\) is satisfiable and if every formula in \(\Sigma\) is a disjunction of at most two literals, then \(\Sigma\) is satisfiable. (A literal is a propositional variable or its negation.) Wojtylak [1999] (listed as Wojtylak [1995])

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