• DocumentCode
    3260662
  • Title

    First-order definable retraction problems for posets and reflexive graphs

  • Author

    Dalmau, Víctor ; Krokhin, Andrei ; Larose, Benoit

  • Author_Institution
    Dept. of Technol., Pompeu Fabra Univ., Barcelona, Spain
  • fYear
    2004
  • fDate
    13-17 July 2004
  • Firstpage
    232
  • Lastpage
    241
  • Abstract
    A retraction from a structure P to its substructure Q is a homomorphism from P onto Q that is the identity on Q. We present an algebraic condition which completely characterises all posets and all reflexive graphs Q with the following property: the class of all posets or reflexive graphs, respectively, that admit a retraction onto Q is first-order definable.
  • Keywords
    combinatorial mathematics; formal logic; graphs; algebraic condition; definable retraction problems; first-order retraction problems; homomorphism; posets; reflexive graphs; structure P; substructure Q; Artificial intelligence; Chromium; Computational complexity; Computer science; Logic; Vocabulary;
  • fLanguage
    English
  • Publisher
    ieee
  • Conference_Titel
    Logic in Computer Science, 2004. Proceedings of the 19th Annual IEEE Symposium on
  • ISSN
    1043-6871
  • Print_ISBN
    0-7695-2192-4
  • Type

    conf

  • DOI
    10.1109/LICS.2004.1319617
  • Filename
    1319617
    • Link To Document
    https://search.isc.ac/dl/search/defaultta.aspx?DTC=49&DC=3260662