A very hard log space counting class

@article{lvarez1990AVH,
  title={A very hard log space counting class},
  author={C. {\`A}lvarez and Birgit Jenner},
  journal={Proceedings Fifth Annual Structure in Complexity Theory Conference},
  year={1990},
  pages={154-168}
}
  • C. Àlvarez, Birgit Jenner
  • Published 1990
  • Mathematics, Computer Science
  • Proceedings Fifth Annual Structure in Complexity Theory Conference
Consideration is given to the logarithmic space counting classes Hash L, opt-L, and span-L, which are defined analogously to their polynomial-time counterparts. Complete functions are obtained for these three classes in terms of graphs and finite automata. It is shown that Hash L and opt-L are both contained in NC/sup 2/, but that, surprisingly, span-L seems to be much harder counting class than Hash L and opt-L. It is demonstrated that span-L-functions can be computed in polynomial time if and… Expand
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