Covering the Baire space by families which are not finitely dominating
نویسندگان
چکیده
It is consistent (relative to ZFC) that each union of max{b, g} many families in the Baire space ω which are not finitely dominating is not dominating. In particular, it is consistent that for each nonprincipal ultrafilter U , the cofinality of the reduced ultrapower ω/U is greater than max{b, g}. The model is constructed by oracle chain condition forcing, to which we give a self-contained introduction.
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ورودعنوان ژورنال:
- Ann. Pure Appl. Logic
دوره 140 شماره
صفحات -
تاریخ انتشار 2006