DF - a feature constraint system and its extension to a logic concurrent language

This paper presents a feature constraint system that, compared with the well-known systems OSFF1] and CFTT5], incorporates several interesting characteristics. The new system, called DF, is naturally extended through the CLP scheme (in combination with a dynamic completion technique) to a logic language equally called DF. 1 The DF feature constraint system adopted the F-logic's 4] declarative semantics, and the DF language successfully puts F-logic to work in a concurrent-avoured manner, with a completely rebuilt operational semantics.