In this paper, we apply a<br />compositional proof technique to an automatic<br />verification of the correctness of<br />Fischer's mutual exclusion protocol. It<br />is demonstrated that the technique may<br />avoid the state-explosion problem. Our<br />compositional technique has recently been<br />implemented in a tool, CMC, which gives<br />experimental evidence that the size of<br />the verification effort required of the technique<br />only grows polynomially in the<br />size of the

more »

... of processes in the<br />protocol. In particular, CMC verifies the<br />protocol for 50 processes within 172.3<br />seconds and using only 32MB main memory.<br />In contrast all existing verification<br />tools for timed systems will suffer from<br />the state-explosion problem, and no tool<br />has to our knowledge succeeded in verifying<br />the protocol for more than 11 processes.