The FIRE (Flexible Information Retrieval Environment) system is an
information retrieval system in which artificial intelligence, or more
precisely knowledge representation, techniques are used in order to
improve the system performance. The parts of FIRE in which such
techniques are used form the so called expert component and they are
concentrated in a specific module named IRES (Information Retrieval
Expert System), described in this document. In such module some of the
competence and capabilities that human intermediaries of information
retrieval systems adopt during the document search activity are
represented. IRES's description is first carried out at a high level
of abstraction, and then it goes further until a level of detail very
near to the code.