lets
+ let <hidden>
| ` <|>
|   + <*>
|   | + <*>
|   | | + pure (\x_0 -> \x_1 -> \x_2 -> (GHC.Types.:) 'a' (x_1 x_2))
|   | | ` satisfy
|   | ` rec <hidden>
|   ` pure (\x_0 -> x_0)
` <*>
  + pure (\x_0 -> GHC.Show.show (x_0 GHC.Types.[]))
  ` ref <hidden>