Separating the notions of self- and autoreducibility

Piotr Faliszewski, Mitsunori Ogihara

Research output: Contribution to journalConference articlepeer-review

1 Scopus citations


Recently Glaßer et al. have shown that for many classes C including PSPACE and NP it holds that all of its nontrivial many-one complete languages are autoreducible. This immediately raises the question of whether all many-one complete languages are Turing self-reducible for such classes C. This paper considers a simpler version of this question-whether all PSPACE-complete (NP-complete) languages are length-decreasing self-reducible. We show that if all PSPACE-complete languages are length-decreasing self-reducible then PSPACE = P and that if all NP-complete languages are length-decreasing self-reducible then NP = P. The same type of result holds for many other natural complexity classes. In particular, we show that (1) not all NL-complete sets are logspace length-decreasing self-reducible, (2) unconditionally not all PSPACE-complete languages are logpsace length-decreasing self-reducible, and (3) unconditionally not all EXP-complete languages are polynomial-time length-decreasing self-reducible.

Original languageEnglish (US)
Pages (from-to)308-315
Number of pages8
JournalLecture Notes in Computer Science
StatePublished - 2005
Externally publishedYes
Event30th International Symposium on Mathematical Foundations of Computer Science 2005, MFCS 2005 - Gdansk, Poland
Duration: Aug 29 2005Sep 2 2005

ASJC Scopus subject areas

  • Theoretical Computer Science
  • Computer Science(all)


Dive into the research topics of 'Separating the notions of self- and autoreducibility'. Together they form a unique fingerprint.

Cite this