Abstract
Monadic Second-Order Unification (MSOU) is Second-Order Unification where all function constants occurring in the equations are unary. Here we prove that the problem of deciding whether a set of monadic equations has a unifier is NP-complete. We also prove that Monadic Second-Order Matching is also NP-complete.
This research has been partially supported by the CICYT Research Projects CADVIAL (TIC2001-2392-C03-01) and LOGFAC (TIC2001-1577-C03-01).
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Levy, J., Schmidt-Schauß, M., Villaret, M. (2004). Monadic Second-Order Unification Is NP-Complete. In: van Oostrom, V. (eds) Rewriting Techniques and Applications. RTA 2004. Lecture Notes in Computer Science, vol 3091. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-540-25979-4_4
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DOI: https://doi.org/10.1007/978-3-540-25979-4_4
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