PROTOS-L System
The PROTOS-L System is a compiler-based system where the compiler does the static type checking and type inferencing, supports the separate compilation and loading of modules, and translates the source code into code for the PROTOS-L Inference Engine (PIE).
Figure 1: Architecture of the PROTOS-L system
The heart of the PIE is the PROTOS Abstract Machine (PAM) an extension of the Warren Abstract Machine to the required polymorphic order-sorted unification. The PAM communicates with another specialized inference system, the Database Inference (DBI) wich realizes a simple deductive DBS over a relational DBMS. The DBI controls the relational DBMS according to read access to relations, updates and transactions, and evaluates deduction rules wich may be recursive; it is complete and terminating for Datalog (function free Horn clauses). There is also an interface to LILOG-DB.
Following the idea to couple indepentently developed subsystems in order to obtain greatest possible flexibility, also the finite domain constraint solver communicates with the PAM over a well-defined interface, providing a seamless integration of constraint solving within normal unification.
The PROTOS Window Manager (PWM) realizes the object-oriented view of OSF/Motif and thus supports the development of sophisticated high-level user interfaces. The compiler of the PROTOS-L system is currently implemented in TEL, and the inference engine is implemented in C. It is available under AIX on IBM RS/6000 (with OSF/Motif and the database systems ORACLE and LILOG-DB), IBM RT/PC 6150 (with SQL/RT), and PS/2.
If you are interested in getting the PROTOS-L system please contact Dr. Peter Bosch at the IBM Institute for Logic and Linguistics in Heidelberg. For more information an the PROTOS-L System you may also contact Prof. Dr. Christoph Beierle or Gregor Meyer at the FernUniversität Hagen.