Computation Engineering: Applied Automata Theory and LogicIt takes more e? ort to verify that digital system designs are correct than it does to design them, and as systems get more complex the proportion of cost spent on veri? cation is increasing (one estimate is that veri? cation complexity rises as the square of design complexity). Although this veri? cation crisis was predicted decades ago, it is only recently that powerful methods based on mathematical logic and automata theory have come to the