Integrating Disequations in the Algebraic and Logic Programming Language LPG

: This paper gives a brief description of the recent improvements of the algebraic and logic programming language lpg. We mainly introduce the possibility to use disequations (negation of equations), which involve user's definable functions, in the definition of predicates. Then we describe the operational semantics of lpg which is based on an extension of SLD\Gammaresolution in order to deal with equations and disequations. Also, we give new sufficient conditions to ensure the completeness of narrowing strategies, to solve equations and disequations, in the presence of conditional term rewrite systems. 1 Introduction During the last few years, many languages have been proposed to combine functional and logic programming paradigms, see for instance [13] for a recent survey. lpg (for Langage de Programmation G'en'erique)[2] is one of these proposals. The lpg language has been designed and implemented in 1985-86 at the IMAG Institute. It is a generic, logic and functional programming l..