The Constraint Logic Programming (CLP) Scheme gave a formal framework, based on constraints, for the basic operational, logical and algebraic semantics of an extended class of logic programs.Expand

This paper investigates transformations and normal forms in the context of Defeasible Logic, a simple but efficient formalism for nonmonotonic reasoning based on rules and priorities.Expand

We describe a scheme for extending CLP(D) to include both required and preferential constraints, with an arbitrary number of strengths of preference.Expand

We present defeasible logic, a less-expressive but more efficient non-monotonic logic that can be used as a modeling language for practical applications, including modelling of regulations and business rules.Expand