6533b7d2fe1ef96bd125e30c

RESEARCH PRODUCT

Positive Versions of Polynomial Time

T. SchwentickIain A. StewartC. Lautemann

subject

Class (set theory)Computational complexity theoryAlgorithmic logicTheoretical Computer ScienceComputer Science ApplicationsCombinatoricsTuring machinesymbols.namesakeMonotone polygonNon-deterministic Turing machineComputational Theory and MathematicsComplexity classsymbolsTime complexityMathematicsInformation Systems

description

Abstract We show that restricting a number of characterizations of the complexity class P to be positive (in natural ways) results in the same class of (monotone) problems, which we denote by posP . By a well-known result of Razborov, posP is a proper subclass of the class of monotone problems in P . We exhibit complete problems for posP via weak logical reductions, as we do for other logically defined classes of problems. Our work is a continuation of research undertaken by Grigni and Sipser, and subsequently Stewart; indeed, we introduce the notion of a positive deterministic Turing machine and consequently solve a problem posed by Grigni and Sipser.

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