Finite failures and partial computations in concurrent logic languages

This paper investigates some semantic properties of concurrentlogiclanguages. Concurrentlogiclanguages with a commit operator differ from pure logiclanguages in the finitefailure set. Since the new finitefailure set depends on the computation rule, we define an operational semantics based on a parallel computation rule and a fair search rule. Failures with a parallel computation rule are shown to be strongly related to partial computed answer substitutions. The set of partial computed answer substitutions and the set of finitefailures are defined as the least fixpoint of a transformation on pairs of interpretations.