lets
+ let <hidden>
| ` <*>
|   + pure (\u1 -> Term)
|   ` ref <hidden>
+ let <hidden>
| ` <*>
|   + pure (\u1 -> u1 Term)
|   ` ref <hidden>
+ let <hidden>
| ` <|>
|   + <*>
|   | + <*>
|   | | + <*>
|   | | | + pure (\u1 -> (\u2 -> (\u3 -> (\u4 -> u1 : u3 u4))))
|   | | | ` conditional
|   | | |   + look
|   | | |   | ` satisfy
|   | | |   + branches
|   | | |   | + <*>
|   | | |   | | + pure (\u1 -> Term)
|   | | |   | | ` satisfy
|   | | |   | + <*>
|   | | |   | | + pure (\u1 -> Term)
|   | | |   | | ` satisfy
|   | | |   | + <*>
|   | | |   | | + pure (\u1 -> Term)
|   | | |   | | ` satisfy
|   | | |   | + <*>
|   | | |   | | + pure (\u1 -> Term)
|   | | |   | | ` satisfy
|   | | |   | + <*>
|   | | |   | | + pure (\u1 -> Term)
|   | | |   | | ` satisfy
|   | | |   | + <*>
|   | | |   | | + pure (\u1 -> Term)
|   | | |   | | ` satisfy
|   | | |   | ` <*>
|   | | |   |   + <*>
|   | | |   |   | + <*>
|   | | |   |   | | + <*>
|   | | |   |   | | | + pure (\u1 -> (\u2 -> (\u3 -> (\u4 -> Term u3))))
|   | | |   |   | | | ` satisfy
|   | | |   |   | | ` ref <hidden>
|   | | |   |   | ` rec <hidden>
|   | | |   |   ` satisfy
|   | | |   ` empty
|   | | ` ref <hidden>
|   | ` rec <hidden>
|   ` pure (\u1 -> u1)
+ let <hidden>
| ` <|>
|   + <*>
|   | + <*>
|   | | + pure (\u1 -> (\u2 -> (\u3 -> u2 u3)))
|   | | ` satisfy
|   | ` rec <hidden>
|   ` pure (\u1 -> u1)
` <*>
  + <*>
  | + pure (\u1 -> (\u2 -> u2))
  | ` ref <hidden>
  ` ref <hidden>