# $EPIC: diff.txt,v 1.2 2006/07/26 19:47:17 sthalik Exp $
======Synopsis:======
$__diff__(<word list 1> / <word list 2>)

======Technical:======
   * There must be a literal slash character ('/') that separates the two word lists.  If it is omitted the empty string is returned.
   * It is not required to have spaces on either side of the slash, but it also does not hurt to have them.
   * The return value is a word list comprised of the negated set-difference of <word list 1> and <word list 2>, that is to say:
   * The return value is a word list of all words that are in ONE BUT NOT BOTH of the word lists.
   * All extra whitespace around words will be lost.
   * Double quoted words are honored, but the double quotes will be lost in the return value.

======Practical:======
Use this function if you need to find the un-common elements of two 
different word lists. 

======Returns:======
All words that are in either <word list 1> or <word list 2> but not both.

======Examples:======
<file>
$diff(one two three / two three four)     returns "one four"
$diff(one two / three four)               returns "one two three four"
</file>