∂14-FEB-75 0958 1,MG Why not tell McCarthy you want to design a formal model of a machine to facilitate rigorous proofs of the correctness of divers implementation hacks. If you like I'll tell him how useful that would be for my 'work` - i.e. I need an implementation to prove correct (of course, telling McCarthy this might be politically unsound [though I can't see why] and be the kiss of death)