> I like the way it's done in cps-tree.sig, assuming that you extended > it this way there: > > structure Cases: > sig > datatype 'a t = > Con of (Con.t * 'a) list > | Int of (int * 'a) list > | Char of (char * 'a) list > | Word of (word * 'a) list > ... > end Yes, that's how I extended it. I will do it the same way for MACHINE.