splay :: Show a => Dec a -> IO ()
display = \case
  Proven a    -> putStrLn $ "success: " ++ show a
  Refuted e _ -> putStrLn $ "failure: " ++ e


display :: Show a => Dec a -> IO ()
display = \case
  Proven a    -> putStrLn $ "success: " ++ show a
  Refuted e _ -> putStrLn $ "failure: " ++ e
display = \case
  Proven a    -> putStrLn $ "success: " ++ show a
  Refuted e _ -> putStrLn $ "failure: " ++ e