Building Dynamic Mathematical

Models with Geometry Expert*

III. A Geometry Deductive Database

Xiao-Shan Gao

xgao@mmrc.iss.ac.cn

Institute of Systems Science

**Academia Sinica**, Beijing 100080

### Abstract

Geometry Expert (GEX) is a software system for dynamic diagram drawing and automated geometry theorem proving and discovering. For a given diagram, we can use GEX to generate a database which contains all the properties of this diagram that can be deduced from a fixed set of geometric rules or axioms, and for each geometric property in the database GEX can generate an elegant proof for it. Based on this software, we introduce the concept of dynamic logic model which can do reasoning itself. Logic models can be used for intelligent educational tasks, such as automated generation of test problems, automated evaluation of students' answers, intelligent tutoring, etc.

?1999. ATCM, Inc