Composition of two semi commutations

  • Y. Roos
  • P. A. Wacrenier
Part of the Lecture Notes in Computer Science book series (LNCS, volume 520)


We give a decidable necessary and sufficient condition on two semi commutations θ1, θ2 such that the composition of \(f_{\theta _1 }\) and \(f_{\theta _2 }\) is a semi commutation function. This characterization uses the commutation graphs of θ1 and θ2, and the non commutation graphs of θ1 and θ 2 −1 . Then we deduce a decidable graphic characterization of confluent semi commutations.


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Copyright information

© Springer-Verlag Berlin Heidelberg 1991

Authors and Affiliations

  • Y. Roos
    • 1
  • P. A. Wacrenier
    • 1
  1. 1.CNRS URA 369, L.I.F.L. Université de Lille 1 U.F.R. I.E.E.A. InformatiqueVilleneuve d'Ascq cedex

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