منابع مشابه
Computational Depth and Reducibility
This paper reviews and investigates Bennett s notions of strong and weak computational depth also called logical depth for in nite binary sequences Roughly an in nite binary sequence x is de ned to be weakly useful if every element of a non negligible set of decidable sequences is reducible to x in recursively bounded time It is shown that every weakly useful sequence is strongly deep This resu...
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We prove that each element of a class of f,anctions (denoted by NPCtP), whose graphs can be accepted in nondeterministic polynomial time, can be evaluated in deterministic polynomial time if and only if '/-reducibility is equivalent to polynomial time many-one reducibility. We also modify the proof technique used to obtain part of this result to obtain the stronger result that if every ,/-reduc...
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The notion of weak truth-table reducibility plays an important role in recursion theory. In this paper, we introduce an elaboration of this notion, where a computable bound on the use function is explicitly specified. This elaboration enables us to deal with the notion of asymptotic behavior in a manner like in computational complexity theory, while staying in computability theory. We apply the...
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We show that the transitivity of pointwise Turing reducibility on the recursively enumerable sets of integers cannot be proven in P− + IΣ1, first order arithmetic with induction limited to Σ1 predicates. We produce a example of intransitivity in a nonstandard model of P+IΣ1 by a finite injury priority construction.
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ژورنال
عنوان ژورنال: Journal of Computer and System Sciences
سال: 1976
ISSN: 0022-0000
DOI: 10.1016/s0022-0000(76)80022-0