Dynamic sort checking by sorting constraint consistency checking

Integrating sorts (types) into logic programming languages increases expressiveness and evaluation efficiency. To support richer sort structures such as parametric and inclusion polymorphism, static sort checking is insufficient. Therefore efficient dynamic sort checking is an important issue in sorted logic programming. We first compare existing techniques for dynamic sort checking in the literature. Aiming to achieve more efficient dynamic sort checking, we propose a new evaluation procedure, based on constraint consistency checking, for sorted logic programs and goals.<>