lambda

gistfile1.lisp

(defun eval (e env)
  (cond ((symbolp e) (cadr (assoc e env)))
        ((eql (car e) 'lambda) (cons e env))
        (t (apply (eval (car e) env) (eval (cadr e) env)))))

(defun apply (f x)
  (eval (cddr (car f)) (cons (list (cadr (car f)) x) (cdr f))))

;; CL-USER> (eval '(((lambda (f) (lambda (x) (f x))) (lambda (a) a)) (lambda (b) b)) '())
;; ((LAMBDA (B) B))