Abstract
In this paper we consider the problem of weak unification of bounded simple set terms. Simple set terms are of the form {e 1, ..., e n}, where e i is a constant or a variable and are much used in deductive database systems such as \(\mathcal{L}\mathcal{D}\mathcal{L}\)and Coral. We consider a restricted form of unification, called “weak unification”, which is mainly used in the field of deductive databases where the database may contain both constants and variables and the program is “safe”. The main result of the paper is the detailed complexity analysis of the weak unification problem by providing a formula for determining the number of weak unifiers.
Work partially supported by a European Union grant under the EU-US project “DEUS EX MACHINA: non-determinism for deductive databases” and by a MURST project “Sistemi formali e strumenti per basi di dati evolute”.
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Greco, S., Mateis, C., Spadafora, E. (1996). The complexity of weak unification of bounded simple set terms. In: Wagner, R.R., Thoma, H. (eds) Database and Expert Systems Applications. DEXA 1996. Lecture Notes in Computer Science, vol 1134. Springer, Berlin, Heidelberg. https://doi.org/10.1007/BFb0034683
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DOI: https://doi.org/10.1007/BFb0034683
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