Understanding diagrams in technical documents

The development of a knowledge base of biological research papers that supports the Scientist´s Assistant, an intelligent system that will provide a scientist with interactive access to the research results, methods, and reasoning in a collection of scientific papers, is discussed. The document understanding system uses graphics constraint grammars for describing and analyzing diagrams, spatial indexing in diagram analysis and understanding, and extension of natural-language processing techniques to complex scientific text. The graphics constraint grammars of the diagram-understanding system are described in detail. Example diagrams and grammars are presented.<>