$not

Usage: $not(x)
Category: conditional

Description:

Returns true if x is empty.

Example:

The following statements will return the values indicated:

$set(foo,)
$not(%foo%)  ==>  "1"   (False)

$not(x)      ==>  ""    (True)
$not( )      ==>  ""    (True)
$not()       ==>  Error