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We describe a totally proper notion of forcing that can be used to shoot uncountable free sequences through certain countably compact non-compact spaces. This is almost (but not quite!) enough to produce a model of ZFC + CH in which countably tight compact spaces are sequential-we still do not know if the notion of forcing described in the paper can be iterated without adding reals.
Let X be an infinite set, and (X) the Boolean algebra of subsets of X. We consider the following statements:
BPI(X): Every proper filter of (X) can be extended to an ultrafilter.
UF(X): (X) has a free ultrafilter.
We will show in ZF (i.e., Zermelo-Fraenkel set theory without the Axiom of Choice) that the following four statements are equivalent:
(i) BPI(ω).
(ii) The Tychonoff product , where 2 is the discrete space 0,1, is compact.
(iii) The Tychonoff product is compact.
(iv) In a Boolean algebra...
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