In Memoriam: John G. Gaschnig

John was best known lately for his work on expert systems, for conversations that helped calibrate my mental compass. He was enthusiastic about and welcomed the added strength that he gave me. Without John, our laboratory is noticeably less than it achieve something truly important. We are proud to have been his colleagues and fortunate John's attitude about my counterarguments was that they I wish he were still here to overcome them.