An inference engine for function free logic programs

The evaluation of function free logic programs by the PROTOS-L system is presented. PROTOS-L is a logic programming language which embeds a module concept, provides read access to external databases and combines order-sorted types with polymorphism. From this viewpoint, PROTOS-L is similar to DATALOG embedded in a typed logic programming language. A small fragment of a travel information system is used to illustrate the evaluation of queries to function free PROTOS-L logic programs.<
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