anchor.diff:    ;; define macros
     (initialize-system-macros)
     (initialize-system-defsetfs)
  -  (initialize-global-vars))
  +  (initialize-global-vars)
  +  (initialize-internal-vars))
   
   (defun initialize-global-vars ()
     (set-global-var '*** nil)
  
positive.code: 
  
  (defparameter *smack-constants*
    '(t nil pi
      ARRAY-DIMENSION-LIMIT ARRAY-RANK-LIMIT ARRAY-TOTAL-SIZE-LIMIT BOOLE-1 BOOLE-2
      BOOLE-AND BOOLE-ANDC1 BOOLE-ANDC2 BOOLE-C1 BOOLE-C2 BOOLE-CLR BOOLE-EQV
      BOOLE-IOR BOOLE-NAND BOOLE-NOR BOOLE-ORC1 BOOLE-ORC2 BOOLE-SET BOOLE-XOR
  
negative.code:       (error "~a is a constant and can not be set." var))
    (set-smackprop var 'global-val val))
  
  (defun set-internal-var (var val)
    (set-smackprop var 'internal-val val))
  
  (defun smack-constantp (symbol)
    (get-smackprop symbol 'constant))
  
  (defun get-internal-var (var)
    (get-smackprop var 'internal-val))
  
  (defun set-func (var val env)
    "Set a variable to a value, in the given or global environment."
  