#'eval., #'evcon., and #'evlis.

gistfile1.cl

(defun eval. (e a)
  (cond
    ((atom e) (assoc. e a (minus1. (length. a '()))))
    ((atom (car e))
     (cond
       ((eq (car e) 'quote) (caadr e))
       ((eq (car e) 'atom)  (atom   (eval. (caadr e) a)))
       ((eq (car e) 'eq)    (eq     (eval. (caadr e) a)  
                                    (eval. (cdadr e) a)))
       ((eq (car e) 'car)   (car    (eval. (caadr e) a)))
       ((eq (car e) 'cdr)   (cdr    (eval. (caadr e) a)))
       ((eq (car e) 'cons)  (cons   (eval. (caadr e) a)
                                    (eval. (cdadr e) a)))
       ((eq (car e) 'cond)  (evcon. (cdr e) a '()))
       ('t (eval. (cons (assoc. (car e) a (minus1. (length. a '())))
                        (cdr e)) a))))
    ((eq (caar e) 'label)
     (eval. (cons (cdadar e) (cdr e))
	    (g-add. (cons (caadar e) (car e)) a '() (length. a '()))))
    ((eq (caar e) 'lambda)
     (eval. (cdadar e)
            (append. a (pair. '() (caadar e) (evlis. (append. '() e '(1)) a '()) '()) '())))))

(defun evcon. (glf a x)
  (cond ((eval. (car (g-nth. x glf '())) a) (eval. (cdr (g-nth. x glf '())) a))
	('t (evcon. glf a (plus1. x)))))

(defun evlis. (glf a x)
  (cond ((eqnum. x (length. glf '()))
	 '())
	('t (append. (cons (eval. (g-nth. x glf '()) a) '()) (evlis. glf a (plus1. x)) '()))))