anchor.diff:  		     :bindings `((,var ,form1)
   				 (,to-var ,form2)
   				 (,by-var ,form3))
  -		     :termination `(when (>= ,var ,to-var) (go end))
  +		     :termination `(when (> ,var ,to-var) (go end))
   		     :step `(incf ,var ,by-var))))
   	       (singleton #'identity
   			  (lambda (x) (and (symbolp x) (not (constantp x)))))
  
positive.code: 		     :bindings `((,by-var ,form1)
  				 (,var ,form2)
  				 (,to-var ,form3))
  		     :termination `(when (>= ,var ,to-var) (go end))
  		     :step `(incf ,var ,by-var))))
  	       (singleton #'identity
  			  (lambda (x) (and (symbolp x) (not (constantp x)))))
  
negative.code: 		     :bindings `((,to-var ,form1)
  				 (,by-var ,form2)
  				 (,var ,form3))
  		     :termination `(when (> ,var ,to-var) (go end))
  		     :step `(incf ,var ,by-var))))
  	       (singleton #'identity
  			  (lambda (x) (and (symbolp x) (not (constantp x)))))
  