Tema3

(defun my-first (lst)
    (CAR lst))

(defun my-rest (lst)
    (CDR lst))

(defun rotate-left (lst)
    (append (CDR lst) (list (CAR lst))))

(defun rotate-right (lst)
    (append (last lst) (reverse (CDR (reverse lst)))))

(defun palindrom (lst)
    (append lst (reverse lst)))

(defun delta (a b c)
    (- (* b b) (* 4 a c)))

(defun is-even (a)
    (= 0 (REM a 2)))

(defun palindromp (a)
    (equal a (reverse a)))

(defun not-realp (a b c)
    (minusp (- (* b b) (* 4 a c))))

(defun absolute (x)
    (COND ((minusp x) (- x))
          (x)))

(defun minimum (a b)
    (COND ((> a b) a)
          (b)))

(defun maximum (a b)
    (COND ((< a b) a)
          (b)))

(defun ec2 (a b c)
    (COND ((minusp (delta a b c)) '())
          ((LIST (/ (+ (* -1 b) (delta a b c)) (* 2 a)) (/ (- (* -1 b) (delta a b c)) (* 2 a))))
    )
)

(defun not-u (a)
    (COND ((equal a t) nil)
          (t)))

(defun or-mine (x y z)
    (COND ((equal x t) t)
          ((equal y t) t)
          ((equal z t) t)
          (nil)))

(defun and-mine (x y z)
    (COND ((equal x nil) nil)
          ((equal y nil) nil)
          ((equal z nil) nil)
          (t)))
(defun median-of-three (x y z)
    (- (+ x y z) (maximum (maximum x y) z) (minimum (minimum x y) z))
)


(print (median-of-three 3 5 8))