laba3_paradigmas

;https://www.cyberforum.ru/lisp/thread1670595.html for 2nd task
;1
(defun summa (m n)
    (cond ((> m n) 0)
    ((evenp n) ( + n (summa m (- n 2))))
    (t (summa m (- n 1)))))
;(print (summa 2 6 ))

;2
(defun counts (w)
  (cond ((null w) 0)
        ((symbolp w) 1)
        ((+ (counts (car w)) (counts (cdr w))))))

;(print(counts '(a (c c (d s s((s))) e)s)))

;3
(defun f(n)
    (cond ((= n 0) 1)
    ((= n 1) 2)
    (t (-(* 2 (f (- n 1)))  (f(- n 2))))
        ) )

;(print (f 4))

;4
(defun create (a n)
    (cond ((= n 0) nil)
    (t(cons (cons a nil) (create a (- n 1))))
        )
            )


;(print(create 2 4))