Re: [Haskell-beginners] `coarbitrary' is not a (visible) method of class `Arbitrary'

Thank you Daniel, that solved it. In case anyone else is struggling with this, here's a revised version of Test.hs which works fine for me. import Char import List import Test.QuickCheck import Text.Printf main = mapM_ (\(s,a) -> printf "%-25s: " s >> a) tests -- reversing twice a finite list, is the same as identity prop_reversereverse s = (reverse . reverse) s == id s where _ = s :: [Int] -- and add this to the tests list tests = [("reverse.reverse/id", quickCheck prop_reversereverse)]