An expert system for the flexible processing of XML-based mathematical knowledge in a PROLOG-environment

In this paper, we describe techniques for querying and transforming XML-based mathematical knowledge. The XML-documents are transformed into an equivalent PROLOG-structure called field notation, which serves as our Document Object Model (DOM). Based on the field notation we provide a powerful and flexible query language in a PROLOG-based logic programming environment enabling intelligent reasoning about the data. It also offers a method which allows for elegantly encoding transfomations on XML-documents, using a powerful substitution mechanism. We are applying these techniques in an expert system for the classification and the retrieval of ordinary differential equations. The rule-based approach allows to provide a query and transformation language, which can deal with different kinds of XML-based mathematical documents, such as documents in MATHML and in OPENMATH.