anchor.diff:  
   ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
   ;;;
  -;;; Methods
  +;;; Functions
   
  -(defmethod make-intermediate-result ((shape shape) (value-fn function))
  +(defun make-intermediate-result (shape value-fn)
     (let ((table (make-hash-table :test #'equal)))
       (loop for index in (set-elements shape) do
         (setf (gethash index table)
  
positive.code: ;;;; © 2016-2018 Marco Heisig - licensed under AGPLv3, see the file COPYING     -*- coding: utf-8 -*-
  
  (in-package :petalisp-reference-backend)
  
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;;;
  ;;; Generic Functions
  
  (defgeneric make-intermediate-result (shape value-fn))
  
  (defgeneric iref (immediate index))
  
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;;;
  
negative.code:       :shape shape
        :table table)))
  
  (defun iref (intermediate-result index)
    (multiple-value-bind (value present-p)
        (gethash index (table intermediate-result))
      (unless present-p
  