tcfail034.hs:17:11: error:
    • Could not deduce (Integral a) arising from a use of ‘mod’
      from the context: (Num a, Eq a)
        bound by the type signature for:
                   test :: forall a. (Num a, Eq a) => a -> Bool
        at tcfail034.hs:16:1-32
      Possible fix:
        add (Integral a) to the context of
          the type signature for:
            test :: forall a. (Num a, Eq a) => a -> Bool
    • In the first argument of ‘(==)’, namely ‘(x `mod` 3)’
      In the expression: (x `mod` 3) == 0
      In an equation for ‘test’: test x = (x `mod` 3) == 0