Obligatory NL ambiguity example. The grammar is small and simple, but exhibits prepositional phrase attachment ambiguity. Example: "the man saw the race with a telescope" Can be bracketed as the following (a) "the man saw (the race with a telescope)" (b) "(the man saw the race) with a telescope" Note: the "lexicon" contains some ambiguous words too - see if you can extend the grammar so this comes into play. "make run" to run the test case. For Hugs, load up Hugs.lhs - it is a simplified version, with entry point "test :: String -> IO ()"