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nil

nil

type: system constant
location: built-in
source file: xlsym.c
Common LISP compatible: yes
supported on: all machines

SYNTAX

nil

DESCRIPTION

The NIL constant represents the empty list or the false value - as oppossed to the true value (the symbol T). NIL can be writen as the 3 character symbol NIL or as the empty list ().

EXAMPLES

(setq myvar NIL)                        ; set MYVAR to False
(setq myvar 'NIL)                       ; NIL and 'NIL evaluate to NIL  
(setq myvar ())                         ; () is the empty list = NIL
(setq myvar '())                        ; () and '() evaluate to NIL
(if nil (print "this won't print")      ; if/then/else
        (print "this will print"))

NOTE: You can not change the value of NIL.


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