T9605.hs:7:6: error:
    • Couldn't match type ‘Bool’ with ‘m Bool’
      Expected: t0 -> m Bool
        Actual: t0 -> Bool
    • In the result of a function call
      In the expression: f1 undefined
      In an equation for ‘f2’: f2 = f1 undefined
    • Relevant bindings include f2 :: m Bool (bound at T9605.hs:7:1)