For a topological space is the ring of all continuous real functions f on X such that, for every real number ϵ > 0, there exists a countable clopen cover of X such that the oscillation of f on each member of is less than ϵ. For a zero-dimensional T 1-space X, the ring and its subring of bounded functions from are applied to necessary and sufficient conditions on X to admit the Banaschewski compactification in the absence of the Axiom of Choice. For a zero-dimensional T 1-space X and a Tychonoff space Y, the problem of when the ring can be isomorphic to or to the ring of all (bounded) continuous real functions on Y is investigated. Several new equivalences of the Boolean Prime Ideal Theorem are deduced. Some results about are obtained under the Principle of Countable Multiple Choices.
Read full abstract