                  (rplacd (quote caar) (quote (expr (lambda (x) (car (car x)))))) 



(rplacd (quote cadr) (quote (expr (lambda (x) (car (cdr x)))))) 


(rplacd (quote cdar) (quote (expr (lambda (x) (cdr (car x)))))) 



(rplacd (quote cddr) (quote (expr (lambda (x) (cdr (cdr x)))))) 


(rplacd (quote cset) (quote (expr (lambda (x y) (rplacd x (list (quote apval) y)))))) 


                                                                                                                     (rplacd (quote xsy) (quote (expr (lambda (x) (prog (y) (setq y oblist) a (cond
 ((null (cdr y)) (return nil)) ((eq x (car (cdr y))) (return (rplacd y (cdr (cdr
 y)))))) (setq y (cdr y)) (go a)))))) 


(rplacd (quote remove) (quote (fexpr (lambda (x y) (prog nil a (cond ((null x) 
(return oblist))) (xsy (car x)) (setq x (cdr x)) go a)))))) 
                                                                                                                                                                 
