Digitizing Interval Duration Logic

  • Gaurav Chakravorty
  • Paritosh K. Pandya
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 2725)


In this paper, we study the verification of dense time properties by discrete time analysis. Interval Duration Logic, (IDL), is a highly expressive dense time logic for specifying properties of real-time systems. Validity checking of IDL formulae is in general undecidable. A corresponding discrete-time logic QDDC has decidable validity.

In this paper, we consider a reduction of IDL validity question to QDDC validity using notions of digitization. A new notion of Strong Closure under Inverse Digitization, SCID, is proposed. For all SCID formulae, the dense and the discrete-time validity coincide. Moreover, SCID has good algebraic properties which can be used to conveniently prove that many IDL formulae are SCID. We also give some approximation techniques to strengthen/weaken formulae to SCID form. For SCID formulae, the validity of dense-time IDL formulae can be checked using the validity checker for discrete-time logic QDDC.


Model Check Time Stamp State Sequence Propositional Variable Validity Checker 
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Copyright information

© Springer-Verlag Berlin Heidelberg 2003

Authors and Affiliations

  • Gaurav Chakravorty
    • 1
  • Paritosh K. Pandya
    • 2
  1. 1.Indian Institute of TechnologyKanpurIndia
  2. 2.Tata Institute of Fundamental ResearchColaba, MumbaiIndia

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