The paper on eyacc is "Practical LR Error Recovery", by S.L. Graham, C.B. Haley, W.N. Joy, SIGPLAN(14,8) August 1979, pp. 168-175. ACM #0-89791-002-8/79/0800-0168 $00.75. It helps a lot in understanding what is really going on in eyacc. -Robert