Dear Sir, I have little trouble with Syf tool. In my university we have Alliance CAD 3.2b version. There after generating VBE file from FSM, I wrote a pattern file. The pattern file is alright there and behaving as the FSM is written. But in my PC I have Alliance CAD 4.0.6. Here generating VBE file from the same FSM I can't match that same pattern file. Not only that in my version it INVERSE THE POLARITY of different flags/output. If I use -I option to stop the inverse, still the pattern doesn't match. Here in the VBE file it assign a significant number of flag/out to '1' but in older version they are assign to some logic. Here it also removes a transition from one to another. Is it not correct that no matter what version I use the same pattern file should match without any modification of pattern file? How I know when to use -I ,-S this kind of option? Why the old version is working properly? Why this kind of contradiction? What I am doing wrong? Waiting for your reply. Mohammad Iftekhar Alam