Fundamental study on structural understanding of mathematical expressions

In this paper, the authors put forward a method to recognize and to understand mathematical expressions based on a rule base and a rough design for the system. Our system for off-line mathematical expression understanding and recognition is composed of five stages, namely preprocessing, character recognition, rule base generation, mathematical expression understanding and translating, with a layout tree and semantic tree. Since understanding of mathematical expressions has certain connection with people's sense and experience, we build a rule base including mathematical rules and some rules based on sense and experience to understand expressions perfectly and to avoid the uncertain problems. Then we discuss on the construction of mathematical rules. In the end, the feasibility and effectiveness of mathematical rules are tested by some experiments.