Nicolas Markey

Résumé

We study the complexity of satisfiability and model-checking of the linear-time temporal logic with past (PLTL). More precisely, we consider several fragments of PLTL, depending on the allowed set of temporal modalities, the use of negations or the nesting of future formulae into past formulae. Our results show that "past is for free", that is it does not bring additional theoretical complexity, even for small fragments, and even when nesting future formulae into past formulae. We also remark that existential and universal model-checking can have different complexity for certain fragments.

@inproceedings{express2002-Mar,
  author =              {Markey, Nicolas},
  title =               {Past is for Free: On the Complexity of Verifying
                         Linear Temporal Properties with Past},
  editor =              {Nestmann, Uwe and Panangaden, Prakash},
  booktitle =           {{P}roceedings of the 9th {I}nternational {W}orkshop
                         on {E}xpressiveness in {C}oncurrency ({EXPRESS}'02)},
  acronym =             {{EXPRESS}'02},
  publisher =           {Elsevier},
  series =              {Electronic Notes in Theoretical Computer Science},
  volume =              {68},
  number =              {2},
  pages =               {89-106},
  year =                {2002},
  month =               aug,
  doi =                 {10.1016/S1571-0661(05)80366-4},
  abstract =            {We study the complexity of satisfiability and
                         model-checking of the linear-time temporal logic
                         with past~(PLTL). More precisely, we consider
                         several fragments of PLTL, depending on the allowed
                         set of temporal modalities, the use of negations or
                         the nesting of future formulae into past formulae.
                         Our~results show that {"}past is for free{"}, that
                         is it does not bring additional theoretical
                         complexity, even for small fragments, and even when
                         nesting future formulae into past formulae. We~also
                         remark that existential and universal model-checking
                         can have different complexity for certain
                         fragments.},
}