منابع مشابه
Banishing Robust Turing Completeness
This paper proves that “promise classes” are so fragilely structured that they do not robustly (i.e. with respect to all oracles) possess Turinghard sets even in classes far larger than themselves. In particular, this paper shows that FewP does not robustly possess Turing hard sets for UP ∩ coUP and IP ∩ coIP does not robustly possess Turing hard sets for ZPP. It follows that ZPP, R, coR, UP∩co...
متن کاملR1-ttSN(NP) Distinguishes Robust Many-One and Turing Completeness
Do complexity classes have many-one complete sets if and only if they have Turingcomplete sets? We prove that there is a relativized world in which a relatively natural complexity class—namely a downward closure of NP, R 1-tt(NP)—has Turing-complete sets but has no many-one complete sets. In fact, we show that in the same relativized world this class has 2-truth-table complete sets but lacks 1-...
متن کاملTuring-Completeness Totally Free
In this paper, I show that general recursive definitions can be represented in the free monad which supports the ‘effect’ of making a recursive call, without saying how these calls should be executed. Diverse semantics can be given within a total framework by suitable monad morphisms. The Bove-Capretta construction of the domain of a general recursive function can be presented datatype-generica...
متن کاملTuring-Completeness of Polymorphic Stream Equation Systems
Polymorphic stream functions operate on the structure of streams, infinite sequences of elements, without inspection of the contained data, having to work on all streams over all signatures uniformly. A natural, yet restrictive class of polymorphic stream functions comprises those definable by a system of equations using only stream constructors and destructors and recursive calls. Using method...
متن کاملTuring Machines , P , NP and NP - completeness
I assume that most students have encountered Turing machines before. (Students who have not may want to look at Sipser’s book [3].) A Turing machine is defined by an integer k ≥ 1, a finite set of states Q, an alphabet Γ, and a transition function δ : Q×Γk → Q×Γk−1×{L, S,R}k where: • k is the number of (infinite, one-dimensional) tapes used by the machine. In the general case we have k ≥ 3 and ...
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ژورنال
عنوان ژورنال: International Journal of Foundations of Computer Science
سال: 1993
ISSN: 0129-0541,1793-6373
DOI: 10.1142/s012905419300016x