holes3.hs:3:5: error:
    • Found hole: _ :: t
      Where: ‘t’ is a rigid type variable bound by
               the inferred type of f :: t at holes3.hs:3:1-5
    • In the expression: _
      In an equation for ‘f’: f = _
    • Relevant bindings include f :: t (bound at holes3.hs:3:1)

holes3.hs:6:7: error:
    • Found hole: _gr :: Char
      Or perhaps ‘_gr’ is mis-spelled, or not in scope
    • In the expression: _gr
      In an equation for ‘g’: g x = _gr
    • Relevant bindings include
        x :: Int (bound at holes3.hs:6:3)
        g :: Int -> Char (bound at holes3.hs:6:1)

holes3.hs:8:5: error:
    • Found hole: _aa :: [Char]
      Or perhaps ‘_aa’ is mis-spelled, or not in scope
    • In the first argument of ‘(++)’, namely ‘_aa’
      In the expression: _aa ++ "a"
      In an equation for ‘h’: h = _aa ++ "a"
    • Relevant bindings include h :: [Char] (bound at holes3.hs:8:1)

holes3.hs:11:15: error:
    • Found hole: _x :: b0
      Where: ‘b0’ is an ambiguous type variable
      Or perhaps ‘_x’ is mis-spelled, or not in scope
    • In the second argument of ‘const’, namely ‘_x’
      In the expression: const y _x
      In an equation for ‘z’: z y = const y _x
    • Relevant bindings include
        y :: [a] (bound at holes3.hs:11:3)
        z :: [a] -> [a] (bound at holes3.hs:11:1)