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Rectangles, Fringes, and Inverses

  • Gunther Schmidt
Part of the Lecture Notes in Computer Science book series (LNCS, volume 4988)

Abstract

Relational composition is an associative operation; therefore semigroup considerations often help in relational algebra. We study here some less known such effects and relate them with maximal rectangles inside a relation, i.e., with the basis of concept lattice considerations. The set of points contained in precisely one maximal rectangle makes up the fringe. We show that the converse of the fringe sometimes acts as a generalized inverse of a relation. Regular relations have a generalized inverse. They may be characterized by an algebraic condition.

Keywords

Generalize Inverse Concept Lattice Relation Algebra Interval Order Algebraic Condition 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2008

Authors and Affiliations

  • Gunther Schmidt
    • 1
  1. 1.Institute for Software Technology, Department of Computing ScienceUniversität der Bundeswehr MünchenNeubibergGermany

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