Lazy narrowing in a graph machine

The paper investigates the implementation of lazy narrowing in the framework of a graph reduction machine. By extending an appropriate architecture for purely functional languages an abstract graph narrowing machine for a functional logic language is constructed. The machine is capable of performing unification and backtracking. The techniques used in functional languages to cope with lazy evaluation are not directly applicable, but must be modified due to the logic component of the implemented language. A prototype implementation of the new machine has been developed.