I went to school at K-State and was best friends with one of the original developers of this software. Eventually, I took a formal logic class with a professor in the philosophy department, Graham. He is involved to a large extent in this as well. One of the best professors I had—-incredibly intelligent and patient and all around good.<p>I would highly recommend people check out Carnap. Having used Z3 and Alloy in other classic, Carnap was by far the best one I used. Very fast and it gave actually useful error messages. It was also so cool how it could represent different types of logic systems. The whole thing is like a cool blag magic to me.