do:
(do ((x a (b x))
          (y c (d y)))
         ((test x y) (z x y))
       (f x y))
局部函数:
(labels ((rec (x y)
            (cond ((test x y)
               (z x y))
              (t 
               (f x y)
               (rec (b x) (d y))))))
       (rec a c))
说明:上面代码中的b,d,test,z,f均为函数。