Formula-Oriented Compositional Minimization in Model Checking

This paper presents a new approach to reduce finite state machines with respect to a CTL formula to alleviate state explosion problem. Reduction is achieved by removing parts useless to the formula of original machines. The main contribution of this paper is to exploit relations among sub formulas of the CTL formula so as to gain more reduction, as well as to extend traditional pruning method, which handles only existential formulas, to handle universal formulas. Based on this kind of reduction, verification of a large system, which usually consists of several components, can be done by evaluating properties on a reduced version of the system, which is built by composing components of the system one by one while doing reduction after each composition. Experimental results show the effectiveness of the approach. Especially when a property is written in a more detailed way, that is to describe the system part by part, the approach has a great potential.