Making doughnuts of Cohen reals
نویسنده
چکیده
For a ⊆ b ⊆ ω with b \ a infinite, the set D = {x ∈ [ω] : a ⊆ x ⊆ b} is called a doughnut. A set S ⊆ [ω] has the doughnut property D , if it contains or is disjoint from a doughnut. It is known that not every set S ⊆ [ω] has the doughnut property, but S has the doughnut property if it has the Baire property B or the Ramsey property R . In this paper it is shown that a finite support iteration of length ω1 of Cohen forcing, starting from L, yields a model for CH + Σ2(D ) + ¬Σ2(B ) + ¬Σ2(R ).
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ورودعنوان ژورنال:
- Math. Log. Q.
دوره 49 شماره
صفحات -
تاریخ انتشار 2003