A Characterization of Mixed Unit Interval Graphs

  • Felix JoosEmail author
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 8747)


We give a complete characterization of mixed unit interval graphs, the intersection graphs of closed, open, and half-open unit intervals of the real line. This is a proper superclass of the well known unit interval graphs. Our result solves a problem posed by Dourado, Le, Protti, Rautenbach and Szwarcfiter (Mixed unit interval graphs. Discrete Math. 312, 3357–3363 (2012)). Our characterization also leads to a polynomial-time recognition algorithm for mixed unit interval graphs.


Unit interval graph Proper interval graph Intersection graph 


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Copyright information

© Springer International Publishing Switzerland 2014

Authors and Affiliations

  1. 1.Institut für Optimierung und Operations ResearchUniversität UlmUlmGermany

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