(
  ;; The code below is used to calculate of the tree hash of a curried function
  ;; without actually doing the curry, and using other optimization tricks
  ;; like unrolling `sha256tree`.

  (defconstant ONE 1)
  (defconstant TWO 2)
  (defconstant A_KW #a)
  (defconstant Q_KW #q)
  (defconstant C_KW #c)

  ;; Given the tree hash `environment-hash` of an environment tree E
  ;; and the tree hash `parameter-hash` of a constant parameter P
  ;; return the tree hash of the tree corresponding to
  ;; `(c (q . P) E)`
  ;; This is the new environment tree with the addition parameter P curried in.
  ;;
  ;; Note that `(c (q . P) E)` = `(c . ((q . P) . (E . 0)))`

  (defun-inline update-hash-for-parameter-hash (parameter-hash environment-hash)
     (sha256 TWO (sha256 ONE C_KW)
                 (sha256 TWO (sha256 TWO (sha256 ONE Q_KW) parameter-hash)
                             (sha256 TWO environment-hash (sha256 ONE 0))))
  )

  ;; This function recursively calls `update-hash-for-parameter-hash`, updating `environment-hash`
  ;; along the way.

  (defun build-curry-list (reversed-curry-parameter-hashes environment-hash)
     (if reversed-curry-parameter-hashes
         (build-curry-list (r reversed-curry-parameter-hashes)
                           (update-hash-for-parameter-hash (f reversed-curry-parameter-hashes) environment-hash))
         environment-hash
     )
  )

  ;; Given the tree hash `environment-hash` of an environment tree E
  ;; and the tree hash `function-hash` of a function tree F
  ;; return the tree hash of the tree corresponding to
  ;; `(a (q . F) E)`
  ;; This is the hash of a new function that adopts the new environment E.
  ;; This is used to build of the tree hash of a curried function.
  ;;
  ;; Note that `(a (q . F) E)` = `(a . ((q . F)  . (E . 0)))`

  (defun-inline tree-hash-of-apply (function-hash environment-hash)
     (sha256 TWO (sha256 ONE A_KW)
                 (sha256 TWO (sha256 TWO (sha256 ONE Q_KW) function-hash)
                             (sha256 TWO environment-hash (sha256 ONE 0))))
  )

  ;; function-hash:
  ;;   the hash of a puzzle function, ie. a `mod`
  ;;
  ;; reversed-curry-parameter-hashes:
  ;;   a list of pre-hashed trees representing parameters to be curried into the puzzle.
  ;;   Note that this must be applied in REVERSED order. This may seem strange, but it greatly simplifies
  ;;   the underlying code, since we calculate the tree hash from the bottom nodes up, and the last
  ;;   parameters curried must have their hashes calculated first.
  ;;
  ;; we return the hash of the curried expression
  ;;   (a (q . function-hash) (c (cp1 (c cp2 (c ... 1)...))))
  ;;
  ;; Note that from a user's perspective the hashes passed in here aren't simply
  ;; the hashes of the desired parameters, but their treehash representation since
  ;; that's the form we're assuming they take in the acutal curried program.

  (defun puzzle-hash-of-curried-function (function-hash . reversed-curry-parameter-hashes)
     (tree-hash-of-apply function-hash
                         (build-curry-list reversed-curry-parameter-hashes (sha256 ONE ONE)))
  )
)