Properties of the Lattice of Observables in Logic Programming.
Gianluca Amato, Giorgio Levi · 1997
We show several properties of the abstract interpretation settings regarding relationships between precision of semantic operators and abstract domains composition. Then, we apply these results to the framework for logic programs introduced in [3], extended with the new class of operational observables. We prove that the classes of perfect, denotational and operational observables are complete lattices and we discuss some problems that arise studying them. Finally, we show how to use functional dependencies to systematically derive new domains in which our semantic operators enjoy desired precision properties. keywords: logic programming, semantics, compositionality, abstract interpretation, abstract semantics. 1 Introduction Our goal is showing several useful properties enjoyed by the lattice of abstractions introduced in [3] and subsequently developed in [17], [4] and [5]. In these papers, an operational top-down and a denotational bottom-up semantics for positive logic programs are...