*print-length* controls how many elements at a given level are printed. If it is false, there is no limit to the number of components printed. Otherwise, it is an integer indicating the maximum number of elements of an object to be printed. If exceeded, the printer will print "..." in place of the other elements. In the case of a dotted list, if the list contains exactly as many elements as the value of *print-length*, the terminating atom is printed rather than printing "..."

*print-level* and *print-length* affect the printing of an any object printed with a list-like syntax. They do not affect the printing of symbols, strings, and bit vectors.

 (setq a '(1 (2 (3 (4 (5 (6)))))))  (1 (2 (3 (4 (5 (6))))))
 (dotimes (i 8) 









   (let ((*print-level* i)) 
     (format t "~&~D -- ~S~%" i a)))
0 -- #
1 -- (1 #)
2 -- (1 (2 #))
3 -- (1 (2 (3 #)))
4 -- (1 (2 (3 (4 #))))
5 -- (1 (2 (3 (4 (5 #)))))
6 -- (1 (2 (3 (4 (5 (6))))))
7 -- (1 (2 (3 (4 (5 (6))))))
  NIL

 (setq a '(1 2 3 4 5 6))  (1 2 3 4 5 6)
 (dotimes (i 7) 
   (let ((*print-length* i)) 
     (format t "~&~D -- ~S~%" i a))) 
0 -- (...)
1 -- (1 ...)
2 -- (1 2 ...)
3 -- (1 2 3 ...)
4 -- (1 2 3 4 ...)
5 -- (1 2 3 4 5 6)
6 -- (1 2 3 4 5 6)
  NIL

(dolist (level-length '((0 1) (1 1) (1 2) (1 3) (1 4) 
                        (2 1) (2 2) (2 3) (3 2) (3 3) (3 4)))
 (let ((*print-level*  (first  level-length))
       (*print-length* (second level-length)))
   (format t "~&~D ~D -- ~S~%"
           *print-level* *print-length* 
           '(if (member x y) (+ (car x) 3) '(foo . #(a b c d "Baz"))))))
0 1 -- #
1 1 -- (IF ...)
1 2 -- (IF # ...)
1 3 -- (IF # # ...)
1 4 -- (IF # # #)
2 1 -- (IF ...)
2 2 -- (IF (MEMBER X ...) ...)
2 3 -- (IF (MEMBER X Y) (+ # 3) ...)
3 2 -- (IF (MEMBER X ...) ...)
3 3 -- (IF (MEMBER X Y) (+ (CAR X) 3) ...)
3 4 -- (IF (MEMBER X Y) (+ (CAR X) 3) '(FOO . #(A B C D ...)))
  NIL