Lambda Lists is a small little language written in Common Lisp, created a long time ago. It works by simple pattern replacement. Enter: (init-dict) (main) to start the REPL. The syntax of defining a new replacement is: let (foo bar) => (bang whiz) The list on the left is the list to be replaced, the list on the right is what the left list is replaced by. Examples: let (sq ?a) => (?a * ?a) let (cube ?a) => (?a * (sq ?a)) let (number of horns on a unicorn) => (id 1) let (?a !) => (if (?a = 0) (id 1) (?a * ((?a - 1) !))) Lambda Lists was created by Sturm Mabie (sturm@cryptm.org).