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not

not

type: predicate function (subr)
location: built-in
source file: xlbfun.c
Common LISP compatible: yes
supported on: all machines

SYNTAX

(not <expr> )
        <expr>          -       the expression to check

DESCRIPTION

The NOT predicate checks to see if the <expr> is false. T is returned if the expression is NIL, NIL is returned otherwise.

EXAMPLES

(not '())                               ; returns T - empty list
(not ())                                ; returns T - still empty
(setq a NIL)                            ; set up a variable
(not a)                                 ; returns T - value = empty list
                                        ;
(not "a")                               ; returns NIL - not a list
(not 'a)                                ; returns NIL - not a list

NOTE: The NOT predicate is the same function as the NULL predicate.


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