- Makefile (OBJS): added shape.o - README: added section for drill/mill substitutions - lang.l, lang.y: added commands "drill", "empty", "mill", "remainder", and "reset" - lang.y (clear_paths): moved freeing of all paths from "clean" to shared function clear_paths - ops.h, ops.c (try_drill, try_mill): helper functions for "drill" and "mill" commands - shape.h. shape.c (slot, circle): functions to generate toolpaths for basic shapes