Extending constraint logic programming with open functions

The natural representation of solutions of finite constraint satisfaction problems is as a (set of) function(s) or relation(s). In (constraint) logic programming, answers are in the form of substitutions to the variables in the query. This results in a not very declarative programming style where a table has to be presented as a complex term. Recently, stable logic programming, also called answer set programming and abductive logic programming have been proposed as approaches supporting a more...