A hierarchy for nondeterministic time complexity

  title={A hierarchy for nondeterministic time complexity},
  author={Stephen A. Cook},
  journal={Proceedings of the fourth annual ACM symposium on Theory of computing},
  • S. Cook
  • Published 1 May 1972
  • Computer Science
  • Proceedings of the fourth annual ACM symposium on Theory of computing
The purpose of this paper is to prove the following result: Theorem 1 For any real numbers r1, r2, 1 ≤ r1 < r2, there is a set A of strings which has nondeterministic time complexity nr2 but not nondeterministic time complexity nr1 The computing devices are non-deterministic multitape Turing machines. 

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