tcfail072.hs:23:
    Ambiguous type variable(s) `p' in the constraint `Ord p'
    arising from use of `g' at tcfail072.hs:23
    in the definition of function `g': g A

tcfail072.hs:23:
    Ambiguous type variable(s) `q' in the constraint `Ord q'
    arising from use of `g' at tcfail072.hs:23
    in the definition of function `g': g A