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Even Pairs in Bull-reducible Graphs

  • Celina M. H. de Figueiredo
  • Frédéric Maffray
  • Claudia Regina Villela Maciel
Part of the Trends in Mathematics book series (TM)

Abstract

A bull is a graph with five vertices a, b, c, d, e and five edges ab, bc, cd, be, ce. A graph G is bull-reducible if no vertex of G lies in two bulls. An even pair is a pair of vertices such that every chordless path joining them has even length. We prove that for every bull-reducible Berge graph G with at least two vertices, either G or its complementary graph \( \bar G \) has an even pair.

Keywords

Induction Hypothesis Bipartite Graph Pairwise Disjoint Adjacent Vertex Perfect Graph 
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

© Birkhäuser Verlag Basel/Switzerland 2006

Authors and Affiliations

  • Celina M. H. de Figueiredo
    • 1
  • Frédéric Maffray
    • 2
  • Claudia Regina Villela Maciel
    • 3
  1. 1.Departamento de Ciência da Computação, Instituto de MatemáticaUniversidade Federal do Rio de JaneiroRio de Janeiro, RJBrazil
  2. 2.Laboratoire LeibnizCNRSGrenoble CedexFrance
  3. 3.Instituto de MatemáticaUniversidade Federal FluminenseNiterói, RJBrazil

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