Logic Program Schemas, Constraints, and Semi-unification

Program schemas are known to be useful in diierent applications such as program synthesis, transformation, analysis, debugging, teaching : : : This paper tackles two complementary aspects of program schemas. We rst propose a language for the description of program schemas. It is based on a subset of second-order logic, enhanced with constraints and speciic features of program schemas. One of the basic operations on schemas is the semi-uniication of a schema with a program. We then express the semi-uniication process over schemas as rewriting and reduction rules, using CLP techniques, where constraints are used to guide the semi-uniication process.