I have written a prototype tool that is similar in spirit, and in some of its workings, to QuickCheck, but based on exhaustive testing in a bounded space of test values. Sales pitch: wouldn't you like to ... * write test generators for your own types more easily? * be sure that any counter-examples found are minimal? (##) * write properties using existentials as well as universals? * establish complete coverage of a defined test-space? * display counter-examples of functional type? (##) * guarantee repeatable test results? (##) For more details and a Haskell 98 module SmallCheck download the small tar file at: http://www.cs.york.ac.uk/fp/smallcheck0.0.tar If you try it, do let me know how you get on. Comments & suggestions welcome. Colin R -------- (##) There have been versions of QuickCheck with extras that address these issues in other ways.