ExpandSynsFail4.hs:11:22: error:
    • Couldn't match type ‘Bool’ with ‘Int’
      Expected: T Int
        Actual: T Bool
    • In the first argument of ‘f’, namely ‘(undefined :: T Bool)’
      In the second argument of ‘($)’, namely ‘f (undefined :: T Bool)’
      In the expression: putStrLn $ f (undefined :: T Bool)