((define (((execute 1) s d) (pgm) (x))
   (calls ((run 2 2) s s d d)
          (pgm pgm)
          (x (lift ()))))
 (define (((run 2 2) s s d d) (pgm suf) (x y))
   (ifs (ops null? suf)
        y
   (ifs (ops equal? (ops car suf) 'x:=x+1)
	(calld ((run 2 2) s s d d)
	       (pgm (ops cdr suf))
	       ((opd cons (lift 1) x) y))
   (ifs (ops equal? (ops car suf) 'y:=y+1)
	(calld ((run 2 2) s s d d)
	       (pgm (ops cdr suf))
	       (x (opd cons (lift 1) y)))
   (ifs (ops equal? (ops car suf) 'x:=x-1)
	(calld ((run 2 2) s s d d)
	       (pgm (ops cdr suf))
	       ((opd cdr x) y))
   (ifs (ops equal? (ops car suf) 'y:=y-1)
	(calld ((run 2 2) s s d d)
	       (pgm (ops cdr suf))
	       (x (opd cdr y)))
   (ifs (ops equal? (ops car (ops car suf)) 'goto)
	(calls ((run 2 2) s s d d)
	       (pgm (calls ((hop) s s) (pgm (ops cdr (ops car suf))) ()))
	       (x y))
   (ifs (ops equal? (ops car (ops car suf)) 'ifx=0)
	(ifd (opd null? x)
	     (calld ((run 2 2) s s d d)
		    (pgm (calls ((hop) s s)
				(pgm (ops cdr (ops car suf)))
				()))
		    (x y))
	     (calld ((run 2 2) s s d d)
		    (pgm (ops cdr suf))
		    (x y)))
   (ifs (ops equal? (ops car (ops car suf)) 'ify=0)
	(ifd (opd null? y)
	     (calld ((run 2 2) s s d d)
		    (pgm (calls ((hop) s s)
				(pgm (ops cdr (ops car suf)))
				()))
		    (x y))
	     (calld ((run 2 2) s s d d)
		    (pgm (ops cdr suf))
		    (x y)))
	(calls ((run 2 2) s s d d)
	       (pgm pgm)
	       (y x)))))))))))

 (define (((hop) s s) (pgm dest) ())
   (ifs (ops null? dest)
        pgm
        (calls ((hop) s s) ((ops cdr pgm) (ops cdr dest)) ()))))