P-Selectivity, immunity, and the power of one bit

  • Authors:
  • Lane A. Hemaspaandra;Leen Torenvliet

  • Affiliations:
  • Department of Computer Science, University of Rochester, Rochester, NY;ILLC, University of Amsterdam, Amsterdam, The Netherlands

  • Venue:
  • SOFSEM'06 Proceedings of the 32nd conference on Current Trends in Theory and Practice of Computer Science
  • Year:
  • 2006

Quantified Score

Hi-index 0.00

Visualization

Abstract

We prove that P-sel, the class of all P-selective sets, is EXP-immune, but is not EXP/1-immune. That is, we prove that some infinite P-selective set has no infinite EXP-time subset, but we also prove that every infinite P-selective set has some infinite subset in EXP/1. Informally put, the immunity of P-sel is so fragile that it is pierced by a single bit of information. The above claims follow from broader results that we obtain about the immunity of the P-selective sets. In particular, we prove that for every recursive function f, P-sel is DTIME(f)-immune. Yet we also prove that P-sel is not ${\it \Pi}^{p}_{2}$/1-immune.