An effective proof that open sets are Ramsey
نویسندگان
چکیده
منابع مشابه
An effective proof that open sets are Ramsey
Solovay has shown that if O is an open subset of P (ω) with code S and no infinite set avoids O, then there is an infinite set hyperarithmetic in S that lands in O. We provide a direct proof of this theorem that is easily formalizable in ATR0.
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ژورنال
عنوان ژورنال: Archive for Mathematical Logic
سال: 1998
ISSN: 0933-5846,1432-0665
DOI: 10.1007/s001530050095