Centaur: the system

This paper describes the organization of the CENTAUR system and its main components. The system is a generic interactive environment. When given the formal specification of a particular programming language-including syntax and semantics — it produces a language specific environment. This resulting environment includes a structure editor, an interpreter/debugger and other tools, all of which have graphic interfaces. CENTAUR is made of three parts: a database component, that provides standardized representation and access to formal objects and their persistent storage; a logical engine that is used to execute formal specifications; an object-oriented man-machine interface that gives easy access to the system's functions. CENTAUR is essentially written in Lisp (Le_Lisp). The logical engine is Prolog (Mu-Prolog). The man-machine interface is built on top of the virtual graphics facility of Le_Lisp, itself primarily implemented on top of X-Windows.