Abstract
By means of constructing suitable well quasi-orders of free monoids we prove that all maximal solutions of certain systems of language inequalities are regular. This way we deal with a wide class of systems of inequalities where all constants are languages recognized by finite simple semigroups. In a similar manner we also demonstrate that the largest solution of the inequality XK ⊆ LX is regular provided the language L is regular.
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Kunc, M. (2004). Regular Solutions of Language Inequalities and Well Quasi-orders. In: Díaz, J., Karhumäki, J., Lepistö, A., Sannella, D. (eds) Automata, Languages and Programming. ICALP 2004. Lecture Notes in Computer Science, vol 3142. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-540-27836-8_73
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DOI: https://doi.org/10.1007/978-3-540-27836-8_73
Publisher Name: Springer, Berlin, Heidelberg
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