It is shown that in ZF Martin's
-axiom
together with the axiom of countable choice for finite sets imply that
arbitrary powers
2X of a 2-point discrete space are
Baire; and that the latter property implies the following: (a) the
axiom of countable choice for finite sets, (b) power sets of infinite
sets are Dedekind-infinite, (c) there are no amorphous sets, and (d)
weak forms of the Kinna-Wagner principle.
References
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[8] Rubin, H. and D. Scott, ``Some topological theorems equivalent to the Boolean prime ideal theorem,'' Bulletin of the American Mathematical Society, vol. 60 (1954), p. 389.
[9] Shannon, G. P., ``Provable forms of Martin's axiom,'' Notre Dame Journal of Formal Logic, vol. 31 (1990), pp. 382--88.