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On the Power of Counting the Total Number of Computation Paths of NPTMs

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Theory and Applications of Models of Computation (TAMC 2024)

Abstract

In this paper, we define and study variants of several complexity classes of decision problems that are defined via some criteria on the number of accepting paths of an NPTM. In these variants, we modify the acceptance criteria so that they concern the total number of computation paths, instead of the number of accepting ones. This direction reflects the relationship between the counting classes \(\#\textsf{P}\) and \(\textsf{TotP}\), which are the classes of functions that count the number of accepting paths and the total number of paths of NPTMs, respectively. The former is the well-studied class of counting versions of \(\textsf{NP}\) problems, introduced by Valiant (1979). The latter contains all self-reducible counting problems in \(\#\textsf{P}\) whose decision version is in \(\textsf{P}\), among them prominent \(\#\textsf{P}\)-complete problems such as Non-negative Permanent, #PerfMatch and #DNF-Sat.

We show that almost all classes introduced in this work coincide with their ‘# accepting paths’-definable counterparts, thus providing an alternative model of computation for the classes \(\mathsf {\oplus P}\), \(\mathsf {Mod_k P}\), \(\textsf{SPP}\), \(\textsf{WPP}\), \(\mathsf {C_=P}\), and \(\textsf{PP}\). Moreover, for each of these classes, we present a novel family of complete problems which are defined via problems that are \(\textsf{TotP}\)-complete under parsimonious reductions. This way, we show that all the aforementioned classes have complete problems that are defined via counting problems whose existence version is in \(\textsf{P}\), in contrast to the standard way of obtaining completeness results via counting versions of \(\textsf{NP}\)-complete problems. To the best of our knowledge, prior to this work, such results were known only for \(\mathsf {\oplus P}\) and \(\mathsf {C_=P}\).

We also build upon a result by Curticapean, to exhibit yet another way to obtain complete problems for \(\textsf{WPP}\) and \(\textsf{PP}\), namely via the difference of values of the \(\textsf{TotP}\) function #PerfMatch on pairs of graphs. Finally, for the so defined \(\textsf{WPP}\)-complete problem, we provide an exponential lower bound under the randomized Exponential Time Hypothesis, showcasing the hardness of the class.

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References

  1. Achilleos, A., Chalki, A.: Counting computations with formulae: logical characterisations of counting complexity classes. In: Proceedings of MFCS 2023. LIPICs, vol. 272, pp. 7:1–7:15 (2023). https://doi.org/10.4230/LIPICS.MFCS.2023.7

  2. Allender, E., Rubinstein, R.S.: P-printable sets. SIAM J. Comput. 17(6), 1193–1202 (1988). https://doi.org/10.1137/0217075

    Article  MathSciNet  Google Scholar 

  3. Antonopoulos, A., Bakali, E., Chalki, A., Pagourtzis, A., Pantavos, P., Zachos, S.: Completeness, approximability and exponential time results for counting problems with easy decision version. Theoret. Comput. Sci. 915, 55–73 (2022). https://doi.org/10.1016/J.TCS.2022.02.030

    Article  MathSciNet  Google Scholar 

  4. Arenas, M., Muñoz, M., Riveros, C.: Descriptive complexity for counting complexity classes. Logical Methods Comput. Sci. 16(1) (2020). https://doi.org/10.23638/LMCS-16(1:9)2020

  5. Arvind, V., Kurur, P.P.: Graph isomorphism is in SPP. Inf. Comput. 204(5), 835–852 (2006). https://doi.org/10.1016/j.ic.2006.02.002

    Article  MathSciNet  Google Scholar 

  6. Babai, L.: Graph isomorphism in quasipolynomial time [extended abstract]. In: Proceedings of STOC 2016, pp. 684–697 (2016). https://doi.org/10.1145/2897518.2897542

  7. Bakali, E., Chalki, A., Pagourtzis, A.: Characterizations and approximability of hard counting classes below #P. In: Chen, J., Feng, Q., Xu, J. (eds.) TAMC 2020. LNCS, vol. 12337, pp. 251–262. Springer, Cham (2020). https://doi.org/10.1007/978-3-030-59267-7_22

    Chapter  Google Scholar 

  8. Beigel, R., Gill, J.: Counting classes: thresholds, parity, mods, and fewness. Theoret. Comput. Sci. 103(1), 3–23 (1992). https://doi.org/10.1016/0304-3975(92)90084-S

    Article  MathSciNet  Google Scholar 

  9. Cai, J.Y., Hemachandra, L.A.: On the power of parity polynomial time. In: Monien, B., Cori, R. (eds.) STACS 89. LNCS, vol. 349, pp. 229–239. Springer, Heidelberg (1989). https://doi.org/10.1007/BFb0028987

    Chapter  Google Scholar 

  10. Chen, P.C.: Heuristic sampling: a method for predicting the performance of tree searching programs. SIAM J. Comput. 21, 295–315 (1992). https://doi.org/10.1137/0221022

    Article  Google Scholar 

  11. Curticapean, R.: The simple, little and slow things count : on parameterized counting complexity. PhD thesis (2015). https://doi.org/10.22028/D291-26612

  12. Fenner, S.A., Fortnow, L., Kurtz, S.A.: Gap-definable counting classes. J. Comput. Syst. Sci. 48(1), 116–148 (1994). https://doi.org/10.1016/S0022-0000(05)80024-8

    Article  MathSciNet  Google Scholar 

  13. Gill, J.: Computational complexity of probabilistic turing machines. SIAM J. Comput. 6(4), 675–695 (1977). https://doi.org/10.1137/0206049

    Article  MathSciNet  Google Scholar 

  14. Hertrampf, U.: Relations among mod-classes. Theoret. Comput. Sci. 74(3), 325–328 (1990). https://doi.org/10.1016/0304-3975(90)90081-R

    Article  MathSciNet  Google Scholar 

  15. Kiayias, A., Pagourtzis, A., Sharma, K., Zachos, S.: Acceptor-definable counting classes. In: Manolopoulos, Y., Evripidou, S., Kakas, A.C. (eds.) PCI 2001. LNCS, vol. 2563, pp. 453–463. Springer, Heidelberg (2001). https://doi.org/10.1007/3-540-38076-0_29

    Chapter  Google Scholar 

  16. Knuth, D.: Estimating the efficiency of backtrack programs. Math. Comput. 29, 122–136 (1974). https://doi.org/10.2307/2005469

    Article  MathSciNet  Google Scholar 

  17. Köbler, J., Schöning, U., Torán, J.: The Graph Isomorphism Problem: Its Structural Complexity. Progress in Theoretical Computer Science. Birkhäuser/Springer (1993). https://doi.org/10.1007/978-1-4612-0333-9

  18. Ogiwara, M., Hemachandra, L.A.: A complexity theory for feasible closure properties. J. Comput. Syst. Sci. 46(3), 295–325 (1993). https://doi.org/10.1016/0022-0000(93)90006-I

    Article  MathSciNet  Google Scholar 

  19. Pagourtzis, A., Zachos, S.: The complexity of counting functions with easy decision version. In: Proceedings of MFCS, vol. 2006, pp. 741–752 (2006). https://doi.org/10.1007/11821069_64

  20. Papadimitriou, C.H., Zachos, S.K.: Two remarks on the power of counting. In: Cremers, A.B., Kriegel, H.P. (eds.) Theoretical Computer Science. LNCS, vol. 145, pp. 269–276. Springer, Heidelberg (1983). https://doi.org/10.1007/BFb0009651

    Chapter  Google Scholar 

  21. Pay, T., Cox, J.L.: An overview of some semantic and syntactic complexity classes. In: Electronic Colloquium on Computational Complexity, TR18-166 (2018). https://eccc.weizmann.ac.il/report/2018/166

  22. Purdom, P.W.: Tree size by partial backtracking. SIAM J. Comput. 7(4), 481–491 (1978). https://doi.org/10.1137/0207038

    Article  MathSciNet  Google Scholar 

  23. Rao, R.P., Rothe, J., Watanabe, O.: Upward separation for FewP and related classes. Inf. Process. Lett. 52(4), 175–180 (1994). https://doi.org/10.1016/0020-0190(94)90123-6

    Article  MathSciNet  Google Scholar 

  24. Schöning, U.: Graph isomorphism is in the low hierarchy. J. Comput. Syst. Sci. 37(3), 312–323 (1988). https://doi.org/10.1016/0022-0000(88)90010-4

    Article  MathSciNet  Google Scholar 

  25. Simon, J.: On some central problems in computational complexity. PhD thesis (1975)

    Google Scholar 

  26. Toda, S.: PP is as hard as the polynomial-time hierarchy. SIAM J. Comput. 20(5), 865–877 (1991). https://doi.org/10.1137/0220053

    Article  MathSciNet  Google Scholar 

  27. Valiant, L.G.: Relative complexity of checking and evaluating. Inf. Process. Lett. 5(1), 20–23 (1976). https://doi.org/10.1016/0020-0190(76)90097-1

    Article  MathSciNet  Google Scholar 

  28. Valiant, L.G.: The complexity of computing the permanent. Theoret. Comput. Sci. 8(2), 189–201 (1979). https://doi.org/10.1016/0304-3975(79)90044-6

    Article  MathSciNet  Google Scholar 

  29. Valiant, L.G.: Accidental algorithms. In: Proceedings of FOCS, vol. 2006, pp. 509–517 (2006). https://doi.org/10.1109/FOCS.2006.7

  30. Valiant, L.G., Vazirani, V.V.: NP is as easy as detecting unique solutions. Theoret. Comput. Sci. 47, 85–93 (1986). https://doi.org/10.1016/0304-3975(86)90135-0

    Article  MathSciNet  Google Scholar 

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Aknowledgements

Aggeliki Chalki has been funded by the project “Mode(l)s of Verification and Monitorability” (MoVeMnt) (grant no 217987). Sotiris Kanellopoulos and Aris Pagourtzis have been partially supported for this work by project MIS 5154714 of the National Recovery and Resilience Plan Greece 2.0 funded by the European Union under the NextGeneration EU Program.

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Bakali, E., Chalki, A., Kanellopoulos, S., Pagourtzis, A., Zachos, S. (2024). On the Power of Counting the Total Number of Computation Paths of NPTMs. In: Chen, X., Li, B. (eds) Theory and Applications of Models of Computation. TAMC 2024. Lecture Notes in Computer Science, vol 14637. Springer, Singapore. https://doi.org/10.1007/978-981-97-2340-9_18

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  • DOI: https://doi.org/10.1007/978-981-97-2340-9_18

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