anchor.diff:  
   (defun immediates-environment-lookup (var env)
     (cdr (assoc var env)))
  -
  -(defun alive-variable-p (var expr)
  -  (and (member var (flatten-list expr))
  -       t))
   
   (defun immediates (env inst)
     (cond
  
positive.code:      (immediates (empty-immediates-environment)
        (virtual
         (closure
          (inlined fundefs
           (flatten
            (beta (empty-beta-environment)
             (alpha2 (empty-alpha2-environment)
              (alpha1 (empty-alpha1-environment)
               (k-normal (empty-k-normal-environment)
                (expand form))))))))))))))
  
  (defun expand-pic (form)
    (expand form))
  
negative.code: 
  (defun output-functions (program stream)
    (loop for name in (program-names program)
       when (and (not (member name '(main intr)))
                 (program-function-alive-p program name))
       do (destructuring-bind (args body body1 insts)
              (program-by-name program name)
            (declare (ignore args body body1))
            (princ insts stream))))
  
  