lets
+ let <hidden>
| ` <|>
|   + <*>
|   | + <*>
|   | | + pure (\u1 -> (\u2 -> (\u3 -> u1 : u2 u3)))
|   | | ` ref <hidden>
|   | ` rec <hidden>
|   ` pure (\u1 -> u1)
+ let <hidden>
| ` try
|   ` <*>
|     + <*>
|     | + <*>
|     | | + <*>
|     | | | + pure (\u1 -> (\u2 -> (\u3 -> (\u4 -> 'a' : ('b' : ('c' : ('d' : Term)))))))
|     | | | ` satisfy
|     | | ` satisfy
|     | ` satisfy
|     ` satisfy
` <*>
  + <*>
  | + <*>
  | | + pure (\u1 -> (\u2 -> (\u3 -> u1 : u2 Term)))
  | | ` ref <hidden>
  | ` ref <hidden>
  ` eof