Michael Codish

The availability of freeness and sharing information for logic programs has proven useful in a wide variety of applications. However, deriving correct freeness and sharing information turns out to be a complex task. In a recent paper, Codish et al. introduce a domain of abstract equation systems and illustrate the systematic derivation of an abstract unification algorithm for sharing and freeness. This paper follows the same approach, and using a more detailed abstraction, develops a more powerful transition system. The resulting algorithm is more prone to efficient implementation as it computes a single abstract solved form which exhibits sharing, freeness, groundness and linearity information.