MathBrush: A System for Doing Math on Pen-Based Devices

Many on-line (interactive) mathematics recognition systems allow the creation of typeset equations, normally in LaTeX, but they do not support mathematical problem solving. In this paper, we present MathBrush, a system that allows users to draw math input using a pen-input device on a tablet computer, recognizes the math expression, and then supports mathematical transformation and problem solving using back-end Computer Algebra Systems (CAS). We describe the architecture of the MathBrush system, which includes modules that support symbol recognition, semantic analysis, the transfer of recognized expressions to back-end CAS, and interface techniques for interacting with CAS output. We also identify unique challenges associated with recognition for math problem solving, such as the need for deeper semantic analysis than is required by LATEX, and the need to deal with ambiguities in user input. Our experiences serve to inform researchers seeking to design interactive mathematics recognition systems geared toward mathematical problem solving.