Guilhem Gamard ; Aliénor Goubault-Larrecq ; Pierre Guillon ; Pierre Ohlmann ; Kévin Perrot et al. - Hardness of monadic second-order formulae over succinct graphs

lmcs:13799 - Logical Methods in Computer Science, January 6, 2026, Volume 22, Issue 1 - https://doi.org/10.46298/lmcs-22(1:3)2026
Hardness of monadic second-order formulae over succinct graphsArticle

Authors: Guilhem Gamard ; Pierre Guillon ; Kévin Perrot ; Guillaume Theyssier

    Our main result is a succinct counterpoint to Courcelle's meta-theorem as follows: every cw-nontrivial monadic second-order (MSO) property is either NP-hard or coNP-hard over graphs given by succinct representations. Succint representations are Boolean circuits computing the adjacency relation. Cw-nontrivial properties are those which have infinitely many models and infinitely many countermodels with bounded cliquewidth. Moreover, we explore what happens when the cw-nontriviality condition is dropped and show that, under a reasonable complexity assumption, the previous dichotomy fails, even for questions expressible in first-order logic.


    Volume: Volume 22, Issue 1
    Published on: January 6, 2026
    Imported on: June 19, 2024
    Keywords: Computational Complexity, Logic in Computer Science

    Consultation statistics

    This page has been seen 43 times.
    This article's PDF has been downloaded 10 times.