1 (defun reverse-r (seq)
2   (fold-right (lambda (x y)
3 		(append y (list x)))
4 	      nil
5 	      seq))
6 
7 (defun reverse-l (seq)
8   (fold-left (lambda (x y)
9 	       (cons y x))
10 	     nil
11 	     seq))