Nonstandard Methods in Ramsey’s Theorem for Pairs
نویسنده
چکیده
We discuss the use of nonstandard methods in the study of Ramsey type problems, and illustrate this with an example concerning the existence of definable solutions in models of BΣ2 for the combinatorial principles of Ramsey’s Theorem for pairs and cohesiveness.
منابع مشابه
Nonstandard Models in Recursion Theory and Reverse Mathematics
We give a survey of the study of nonstandard models in recursion theory and reverse mathematics. We discuss the key notions and techniques in effective computability in nonstandard models, and their applications to problems concerning combinatorial principles in subsystems of second order arithmetic. Particular attention is given to principles related to Ramsey’s Theorem for Pairs.
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