anchor.diff:  			    (keyword-parser 'upto)
   			    (keyword-parser 'below))
   	       (singleton #'identity (constantly t))
  -	       (alternative (keyword-parser 'from)
  -			    (keyword-parser 'upfrom))
  -	       (singleton #'identity (constantly t))))
  +	       (alternative 'from-parser 'upfrom-parser)))
   
   ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
   ;;;
  
positive.code: ;;; omitted).
  
  (define-parser arithmetic-up-13-parser
    (consecutive (lambda (var type-spec from form1)
  		 (declare (ignore from))
  		 (make-instance 'for-as-arithmetic
  		   :bindings `((,var ,form1))
  		   :termination nil
  		   :step `(incf ,var)))
  	       'simple-var-parser
  	       'type-spec-parser
  	       (alternative (keyword-parser 'from)
  			    (keyword-parser 'upfrom))
  	       (singleton #'identity (constantly t))))
  
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;;;
  
negative.code: 
  ;;; Order is FROM/UPFROM TO/UPTO BY.
  (define-parser arithmetic-up-1-parser
    (consecutive (lambda (var type-spec from to form2 by)
  		 (let ((to-var (gensym))
  		       (by-var (gensym)))
  		   (make-instance 'for-as-arithmetic
  		     :bindings `((,var ,from)
  				 (,to-var ,form2)
  				 (,by-var ,by))
  		     :termination
  