Linear weak alternating automata and the model checking problem

Diploma Thesis

Moritz Hammer

Abstract

Automata-based model checking is a widely used approach towards software model checking. Traditionally, nondeterministic Buechi automata are used to represent the temporal logic property to be checked. We take a look at a special kind of alternating automata, the linear weak alternating automata. They can be constructed from LTL formula in an elegant way in linear time. The emptiness check on linear weak alternating automata, on the other hand, requires exponential time, whereas the emptiness of nondeterministic Büuchi automata, being of exponential size with respect to the size of the LTL formula they represent, can be checked in linear time. We try take advantage of the better constructibility of linear weak alternating automata in model checking by implementing a model checker using "on-the-fly generalized Buechi automata generation". The emptiness check is conducted using an extended version of Tarjan's algorithm. After obtaining promising results, we adapt the SPIN model checker to the new algorithm.

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Moritz Hammer
Last modified: Tue Apr 12 11:22:45 CEST 2005