The Veblen functions for computability theorists
نویسندگان
چکیده
منابع مشابه
The Veblen functions for computability theorists
We study the computability-theoretic complexity and proof-theoretic strength of the following statements: (1) “If X is a well-ordering, then so is εX ”, and (2) “If X is a well-ordering, then so is φ(α,X )”, where α is a fixed computable ordinal and φ represents the two-placed Veblen function. For the former statement, we show that ω iterations of the Turing jump are necessary in the proof and ...
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ژورنال
عنوان ژورنال: The Journal of Symbolic Logic
سال: 2011
ISSN: 0022-4812,1943-5886
DOI: 10.2178/jsl/1305810765