Ions and local definitions in logic programming
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In  Bowen and Kowalski suggest amalgamating language and metalanguage in logic programming in order to be able to explicitly refer to theories (i.e. collections of clauses), and discuss derivability from these theories. In particular, they use amalgamation in order to give a solution to the locality of definition problem. In this paper we reconsider this locality of definition problem, and present a new approach for solving it, whithout calling upon language and metalanguage amalgamation. To this end we introduce the notion of an ion, and extend to logic programming with ions various results from "classical" logic programming. We give a least fixpoint semantics, a set-theoretic characterization of successful derivations, and a skylight theorem characterizing approximations to the result computed by a given derivation.
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- [ 1].Bowen K.A. and Kowalski R.A.: Amalgamating language and metalanguage, in Logic Programming, K.L. Clark and T.-S. Taernlund ed, Academic Press (1982), pp 153–172Google Scholar
- [ 2].Clark K.L.: Logic as a computational formalism, Research monograph 79/59 DOC, Imperial College (1979).Google Scholar
- [ 3].
- [ 4].van Emden M.H. and Nait Abdallah M.-A.: Top-down semantics of fair derivations in logic programs, Journal of Logic Programming (1985), 1 pp 67–75Google Scholar
- [ 5].Kowalski R.: Logic for problem solving, Elsevier North Holland, New York (1979).Google Scholar
- [ 6]Nait Abdallah M.-A.: On the interpretation of infinite computations in logic programming, Springer LNCS # 172, pp 358–370 (1984)Google Scholar
- [ 7].
- [ 8]Sacerdoti et al.: QLISP, a language for the interactive development of complex systems, SRI AI Center, Technical Note 120 (1976)Google Scholar