Temporal Reasoning in Nested Temporal Networks with Alternatives

  • Roman Barták
  • Ondřej Čepek
  • Martin Hejna
Part of the Lecture Notes in Computer Science book series (LNCS, volume 5129)


Temporal networks play a crucial role in modeling temporal relations in planning and scheduling applications. Temporal Networks with Alternatives (TNAs) were proposed to model alternative and parallel processes in production scheduling, however the problem of deciding which nodes can be consistently included in such networks is NP-complete. A tractable subclass, called Nested TNAs, can still cover a wide range of real-life processes, while the problem of deciding node validity is solvable in polynomial time. In this paper, we show that adding simple temporal constraints (instead of precedence relations) to Nested TNAs makes the problem NP-hard again. We also present several complete and incomplete techniques for temporal reasoning in Nested TNAs.


Feasible Solution Temporal Constraint Output Label Temporal Network Base Graph 
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Copyright information

© Springer-Verlag Berlin Heidelberg 2008

Authors and Affiliations

  • Roman Barták
    • 1
  • Ondřej Čepek
    • 1
  • Martin Hejna
    • 1
  1. 1.Faculty of Mathematics and PhysicsCharles University in PraguePraha 1Czech Republic

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