not - boolean negation
LIBRARY
(import (rnrs)) ;R6RS
(import (rnrs base)) ;R6RS
(import (scheme r5rs)) ;R7RS
(import (scheme base)) ;R7RS
SYNOPSIS
(not obj)
DESCRIPTION
Returns
#t
if
obj
is false, and returns
#f
otherwise.
RETURN VALUES
Returns a single value; a boolean.
EXAMPLES
(not #t) => #f
(not 3) => #f
(not (list 3)) => #f
(not #f) => #t
(not '()) => #f
(not (list)) => #f
(not 'nil) => #f
COMPATIBILITY
This procedure works the same in all Schemes.
ERRORS
This procedure can raise exceptions with the following condition types:
- &assertion (R6RS)
-
The wrong number of arguments was passed.
- R7RS
-
The assertions described above are errors.
Implementations may signal an error, extend the procedure's
domain of definition to include such arguments,
or fail catastrophically.
SEE ALSO
if(7scm),
boolean=?(3scm)
STANDARDS
R4RS,
IEEE Scheme,
R5RS,
R6RS,
R7RS
HISTORY
The
not
function has been in Scheme since the beginning, even when it ran on
MacLisp, and it was also present in LISP 1.5.
AUTHORS
This page is part of the
scheme-manpages
project.
It includes materials from the RnRS documents.
More information can be found at
https://github.com/schemedoc/manpages/.
Markup created by unroff 1.0sc, March 04, 2023.