;;NOTIUNI DE BAZA
pi
16
1.25
a ;unbound variable
"Sir de caractere"

()
(a b c)
(a (b (c)))
(+ 1 2 3)
(aceasta este o lista)

;;CONSTANTE
t
nil
()

;;;; Calcul factorial
;;;
(defun fact (n)
	;; consitaia de oprire
	(if (zerop n) 
		1	; 1<--(fact 0)
		;;apel recursiv
		(* n (fact (- n 1)))
	)
)

;;FUNCTII
(+ 1 2 3)
(* (+ 2 3) 10)
(sqrt 4)
(sqrt 3)
(sqrt (sqrt 4))
(a 1 2) ; unbound function a

;;EVALUAREA
(quote a)
(quote (a b c))
'a
'(a b c)
(eval '(+ 1 2))
(car '(+ 1 2))
(eval y) ;; x-->10, y-->x

;ATRIBUIREA SI LEGAREA VARIABILELOR
(setq x 1 y '(a b c))
(setq x 1 y (+ x 2))

(setq x 10)                     
(setq x 1 y (+ x 2)) ;;x=1, y=3
(setq x 10)            
(psetq x 1 y ( + x 2));;x=1 y=12

;;OPERATII CU LISTE
(car '(a b c))
(first '(a b c))
(second '(a b c d e))
(third '(a b c d e))
(4th '(a b c d e))
(car '((a (b c)) d ((e f) g) h)) 
(car 'a)

(cdr '(a b c))
(cdr '((a (b c)) d ((e f) g) h)) 
(cdr 'a)
(rest '(a b c))

(cons 'a '(b c))
(cons '(a) '(b c))
(cons 1 nil)      
(cons nil nil)    
(cons 1 2)        
(cons '(a b) 'c)  
(setq l '(a b c)
(cons (car l) (cdr l))

(append '(a) '(b c))                 
(append '((a) b) '(c) '(d (e f)))    
(append 'a '(b c)) ;;error: bad argument type - a           
(append '((a)) '(b c) 'd) ;; ((a) b c . d)                          
(append)

(list 1 2 3)                   
(list '(a b) 'c '((d e) f))    
(list 1 '(2 . 3))              
(list nil nil)                 

(cons '(a) '(b c)) ;;((a) b c)                        
(append '(a) '(b c)) ;;(a b c)                          
(list '(a) '(b c)) ;;((a) (b c))                      

(last '(a b c d))
(last '(a b . c))
(last (a))

(reverse '(1 2 3 4 5))
(reverse '( a (b c d) e))

(length '(a b c))
(length '((a b (c)) (d e)))
(length ())


(cond 	((> x 0) x)
	((< x 0) (- 0 x))     
	(t 0)
)             

(defun putere (x)
	(* x x))

;;(or a b) =  (cond (a) (b))
;;(and a b) = (cond (a b))