Lisp Command Summary

+ - * /         (+ (* 3 5) (/ 24 (- 9 1)))    15 + 24 / 8 = 18

setq            (setq x 3)                    X = 3
                (setq y '(a b))               X = '(a b)

set             (set (car '(x y z)) 3)        X = 3
                (setq a 'b) (set a 4)         B = 5
      setq ... = set '...

car             (car '(a b c d))              A
                (car '((a b) c c))            (A B)

cdr             (cdr '(a b c d))              (B C D)

cons            (cons 3 '(4 5))               (3 4 5)
                (cons (car x) (cdr x))        X

list            (list 3 '(4 5))               (3 (4 5))

defun           (defun square (x) (* x x))    function for squaring

                (defun factorial (n)          function for factorial
                    (cond ((zerop n) 1)
                          (t (* n (factorial (- n 1)))))

if              (if (> x 1) (+ 2 3) (- 2 3))  if X>1 then return 5 else -1

cond            (cond ((= x 4) 'A) 
                      ((= x 3) 'B)
                      ((= x 2) 'C)))

reverse         (reverse '(a b c d))          (d c b a)

atom            (atom 3)                      t
                (atom '(a b))                 f

listp           (listp 3)                     f
                (listp '(a b))                t

eval            (setq x '(+ 3 5))   (eval x)  8

apply           (apply '+ '(1 2 3 4))         10

mapcar          (mapcar 'atom '(1 2 (3 4) 5))              (t t f t)
                (mapcar '+ '(2 4 1) '(7 1 2))              (9 5 3)

lambda          ((lambda (x, y) (cons y x)) '(b c) 'a)     (a b c)
                ((lambda (x) (cons (car x) (cdr x))) '(a b c d)     (a b c d)

let             (let ((x 3) (y 4))             25
                     (+ (* x x) (* y y)))