Reductions to sets of low information content

V. Arvind, Y. Han, L. Hemachandra, J. Köbler, A. Lozano, M. Mundhenk, M. Ogiwara, U. Schöning, R. Silvestri, T. Thierauf

Research output: Chapter in Book/Report/Conference proceedingConference contribution

6 Scopus citations


In this paper we study the complexity of sets that reduce to sparse sets (and tally sets), and the complexity of the simplest sparse sets to which such sets reduce. We show even with respect to very flexible reductions that NP cannot have sparse hard sets unless P = NP; an immediate consequence of our results is: If any NP-complete set conjunctively reduces to a sparse set, then P = NP. We also show that any set A that reduces to some sparse set (via various types of reductions) in fact reduces by the same type of reduction to a sparse set that is simple relative to A. We give a complete characterization of the sets of low instance complexity in terms of reductions to tally sets; it follows that if P ≠ NP, then no set of low instance complexity can be complete for NP with respect to disjunctive reductions or conjunctive reductions.

Original languageEnglish (US)
Title of host publicationAutomata, Languages and Programming - 19th International Colloquium, Proceedings
EditorsWerner Kuich
PublisherSpringer Verlag
Number of pages12
ISBN (Print)9783540557197
StatePublished - 1992
Externally publishedYes
Event19th International Colloquium on Automata, Languages, and Programming, ICALP 1992 - Wien, Austria
Duration: Jul 13 1992Jul 17 1992

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume623 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


Other19th International Colloquium on Automata, Languages, and Programming, ICALP 1992

ASJC Scopus subject areas

  • Theoretical Computer Science
  • Computer Science(all)


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