NIL 

10. 


(DEFPROP IBASE 
 (NIL . 10.) 
VALUE)

(DEFPROP BASE 
 (NIL . 10.) 
VALUE)

(DEFPROP PICKIT 
 (LAMBDA(L N)
  (PROG (M I J L1)
	(SETQ J (ADD1 (LENGTH L)))
   L1   (SETQ I 1.)
	(SETQ L1 L)
   L    (COND ((NULL L1) (RETURN N))
	      ((OR (EQ (CAR L1) N)
		   (EQ (PLUS (CAR L1) I) (PLUS N J))
		   (EQ (DIFFERENCE (CAR L1) I) (DIFFERENCE N J)))
	       (GO AGAIN)))
	(SETQ L1 (CDR L1))
	(SETQ I (ADD1 I))
	(GO L)
   AGAIN
	(SETQ N (ADD1 N))
	(COND ((GREATERP N 8.) (RETURN NIL)))
	(GO L1))) 
EXPR)

(DEFPROP QUEEN 
 (LAMBDA NIL
  (PROG (ANS N M CONTEXT)
	(SETQ N 1.)
   L    (COND ((EQ (LENGTH ANS) 8.) (RETURN ANS)))
   LL   (PRINT (LIST ANS N))
	(SETQ M (PICKIT ANS N))
	(COND
	 (M (SETQ CONTEXT (CONS (CONS M ANS) CONTEXT)) (SETQ ANS (APPEND ANS (LIST M))) (SETQ N 1.) (GO L)))
   LLL  (SETQ N (CAAR CONTEXT))
	(SETQ ANS (CDAR CONTEXT))
	(SETQ CONTEXT (CDR CONTEXT))
	(SETQ N (ADD1 N))
	(COND ((GREATERP N 8.) (GO LLL)))
	(GO LL))) 
EXPR)

NIL