October, 1986.

We introduce a new paradigm for the integration of functional and logic programming. Unlike most current research, our approach is not based on extending unification to general-purpose equation solving. Rather, we propose a com- putation delaying mechanism called residuation. This allows a clear distinction between functional evaluation and logical deduction. The former is based on the λ-calculus, and the latter on Horn clause resolution. In clear contrast with equation-solving approaches, our model supports higher-order function evaluation and efficient compilation of both functional and logic programming expressions, without being plagued by non-deterministic term-rewriting. In addition, residuation lends itself naturally to process synchronization and constrained search. Besides unification (equations), other residuations may be any ground-decidable goal, such as mutual exclusion (inequations), and com- parisons (inequalities). We describe an implementation of the residuation paradigm as a prototype language called Le Fun—Logic, equations, and Functions.

@inproceedings{slp88,
    AUTHOR = {Hassan Ait-Kaci and Patrick Lincoln and and Roger Nasr},
    TITLE = {Le Fun: Logic, Equations, and Functions},
    YEAR = {1986},
    MONTH = {October},
    URL = {http://www.csl.sri.com/papers/slp88/}
}

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