lets
+ let <hidden>
| ` <|>
|   + <*>
|   | + <*>
|   | | + pure (\u1 -> (\u2 -> (\u3 -> u1 (u2 u3))))
|   | | ` <*>
|   | |   + pure cons
|   | |   ` <*>
|   | |     + <*>
|   | |     | + pure (\u1 -> (\u2 -> u1))
|   | |     | ` pure 'r'
|   | |     ` satisfy
|   | ` rec <hidden>
|   ` pure (\u1 -> u1)
` <*>
  + pure Term
  ` <*>
    + <*>
    | + pure (\u1 -> (\u2 -> u1))
    | ` <*>
    |   + ref <hidden>
    |   ` pure Term
    ` eof