>So, Yacc, Bison, Prolog and some parts of List are simply a different way >of thinking, that solves certain kinds of problems very efficiently (among >them mail routing, AI, and recursive descent parsers). You can't expect to >be able to produce a good Prolog or Bison program because you know C and >assembly for 10 years. The compiler was for a procedural language (this was 15 years ago) roughly a cross between BASIC and C. Initial version was to be an interpreter, later to assembly source. I did them reverse, because it was easier for me to think that way. This was a senior-level class. We had already learned LISP, Prolog, and a host of other languages at this point, and were each using 3+ operating systems regularly (VMS, Unix (on an LSI box), OS/JCL for IBM 380(?), DOS, and Apple DOS, TRS-DOS were the big ones). Andy ================================================================== Andy Kunz - Statistical Research, Inc. - Westfield, New Jersey USA ==================================================================