Epistemology versus Ontology - Essays on the Philosophy and Foundations of Mathematics in Honour of Per Martin-Löf
Epistemology versus Ontology - Essays on the Philosophy and Foundations of Mathematics in Honour of Per Martin-Löf
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认识论与本体论 - 纪念佩尔·马丁-洛夫的数学哲学和基础论文
DOI:
10.1007/978-94-007-4435-6_15
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发表时间:
2012
期刊:
影响因子:
--
通讯作者:
Rathjen M
中科院分区:
文献类型:
--
作者:
Rathjen M
Full intuitionistic Zermelo-Fraenkel set theory,IZF, is obtained from constructive Zermelo-Fraenkel set theory,CZF, by adding the full separation axiom scheme and the power set axiom. The strength ofCZFplus full separation is the same as that of second order arithmetic, using a straightforward realizability interpretation in classical second order arithmetic and the fact that second order Heyting arithmetic is already embedded inCZFplus full separation. This paper is concerned with the strength ofCZFaugmented by the power set axiom,. It will be shown that it is of the same strength as Power Kripke–Platek set theory,, as well as a certain system of type theory,, which is a calculus of constructions with one universe. The reduction oftouses a realizability interpretation wherein a realizer for an existential statement provides a set of witnesses for the existential quantifier rather than a single witness. The reduction oftoemploys techniques from ordinal analysis which, when combined with a special double negation interpretation that respects extensionality, also show thatcan be reduced toCZFwith the negative power set axiom. AsCZFaugmented by the latter axiom can be interpreted inand this type theory has a types-as-classes interpretation in, the circle will be completed.