anchor.diff:  					  x
   					  (find-next-tag (cdr x)))))
   
  -		 will-be-set-again?
  -		   #'((x v)
  -			    (when (and x
  -						   ; We don't know what happens after a jump.
  -						   (not (vm-jump? (car x))))
  -				  (or (and (%setq? (car x))
  -						   (eq v (second (car x))))
  -					  ; Variable will be used - don't remove setter.
  -					  (unless (find-tree (car x) v))
  -					    (will-be-set-again? (cdr x) v))))
  -
  +		 ; Remove code without side-effects whose result won't be used.
   		 remove-code
   		   #'((x)
   				(when x
  
positive.code: ;;;;; Peephole-optimizer for expression-expanded code.
  
  (defun find-tree (x v)
    (if (atom x)
  	  (eq x v)
  	  (or (find-tree (car x) v)
  	      (find-tree (cdr x) v))))
  
  (defun opt-peephole (x)
    (with (removed-tags nil
  		 find-next-tag
  		   #'((x)
  			    (when x
  
negative.code: 						     (is-lambda? (third a)))
  					    (cons `(%setq ,(second a)
  							     #'(,(lambda-args  (third a))
  								     ,@(reduce-tags (lambda-body (third a)))))
  						      (reduce-tags d))
  						; Remove first of two subsequent tags.
      		            (if (and a (car d)
  								 (atom a)
  