Mathematical systems theory

, Volume 10, Issue 1, pp 19–32

Relativization of questions about log space computability


  • Richard E. Ladner
    • Department of Computer ScienceUniversity of Washington
  • Nancy A. Lynch
    • Department of MathematicsUniversity of Southern California

DOI: 10.1007/BF01683260

Cite this article as:
Ladner, R.E. & Lynch, N.A. Math. Systems Theory (1976) 10: 19. doi:10.1007/BF01683260


A notion of log space Turing reducibility is introduced. It is used to define relative notions of log space, A , and nondeterministic log space, . These classes are compared with the classes and which were originally defined by Baker, Gill, and Solovay [BGS]. It is shown that there exists a computable setA such that . Furthermore, there exists a computable setA such that and . Also a notion of log space truth table reducibility is defined and shown to be equivalent to the notion of log space Turing reducibility.

Copyright information

© Springer-Verlag New York Inc. 1976