Complexity cores and hard problem instances

  • Uwe Schöning
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 450)


Many intractable problems such as NP-complete problems (provided PNP) have easy subproblems. In contrast, we investigate the existence and the properties of inherently hard subproblems, called complexity cores. Furthermore, the question is posed whether individual problem instances can be inherently hard (for all algorithms solving the problem), and this question is answered positively.


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Copyright information

© Springer-Verlag Berlin Heidelberg 1990

Authors and Affiliations

  • Uwe Schöning
    • 1
  1. 1.Universität UlmWest Germany

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