Interpreting weak Kőnig's lemma in theories of nonstandard arithmetic
نویسندگان
چکیده
We show how to interpret weak König’s lemma in some recently defined theories of nonstandard arithmetic in all finite types. Two types of interpretations are described, with very different verifications. The celebrated conservation result of Harvey Friedman about weak König’s lemma can be proved using these interpretations. We also address some issues concerning the collecting of witnesses in herbrandized functional interpretations.
منابع مشابه
Weak Theories of Nonstandard Arithmetic and Analysis
A general method of interpreting weak higher-type theories of nonstandard arithmetic in their standard counterparts is presented. In particular, this provides natural nonstandard conservative extensions of primitive recursive arithmetic, elementary recursive arithmetic, and polynomial-time computable arithmetic. A means of formalizing basic real analysis in such theories is sketched. §
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عنوان ژورنال:
- Math. Log. Q.
دوره 63 شماره
صفحات -
تاریخ انتشار 2017