Towards resource handling in logic programming: The PPL framework and fits semantics

The PPL framework is proposed as a simple extension to logic programming aiming at handling resources. It is argued that the separation between logical treatments and resource handling is desirable and, to that end, resources are proposed to be manipulated by means of pre- and post-conditions associated with usual Horn clauses. The expressiveness of the resulting framework is evidenced through the coding of several applications. Operational and declarative semantics are also presented as extensions of the classical ones accounting for the evaluation of pre- and post-conditions, in particular the non-monotonic behavior of the world of resources they induce in general.