Jed Brown writes: > On 13 Jan 2008, frr149 at easyjob.net wrote: >> >> If I define the follwoing functions: >> >> car (x:_) = x >> car [] = [] > > This won't typecheck. It helps to add a type signature > car :: [a] -> a Good will, wrong diagnosis. This WILL check. car :: forall a. [[a]] -> [a] J. Karczmarczuk