Hi Dmitry,
   The stylesheet below will compare two lists. Ordering is ignored, and 
duplicates are allowed and are ignored.

I am preparing string hash of two lists, and then comparing the hashes. 
Also, node-set extension function is being used.

Please also note that this solution is not namespace aware.

The XSLT processor used is MSXSL 4.0.

The XML used is -

<lists>
  <list1>
    <item name="aaa"/>
    <item name="bbb"/>
  </list1>
  <list2>
    <item name="aaa"/>
    <item name="bbb"/>
    <item name="ccc"/>
   </list2>
</lists>

The stylesheet is -

<?xml version='1.0'?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
                       xmlns:msxsl="urn:schemas-microsoft-com:xslt"
                       version="1.0">

<xsl:output method="text" encoding="UTF-8" />

<xsl:key name="dup" match="*" use="." />

<xsl:template match="/lists">
   
   <!-- process 1st list -->
   <xsl:variable name="l" select="list1" />
   
   <xsl:variable name="x">
     <xsl:for-each select="list1/*">          
       <temp pos="{position()}">
         <xsl:value-of select="local-name()" />
         <xsl:for-each select="@*">
           <xsl:value-of select="local-name()" />
           <xsl:value-of select="." />
         </xsl:for-each>
       </temp>
     </xsl:for-each>
   </xsl:variable>
   
   <xsl:variable name="listA">
     <xsl:for-each select="msxsl:node-set($x)/temp[generate-id() = 
generate-id(key('dup', .)[1])]">
       <xsl:sort select="." />
       <xsl:variable name="pos" select="@pos" />
       <xsl:copy-of select="$l/*[position() = $pos]" />
     </xsl:for-each>
   </xsl:variable>
   
   <xsl:variable name="hash1">
     <xsl:for-each select="msxsl:node-set($listA)/*">
       <xsl:value-of select="local-name()" />
       <xsl:for-each select="@*">
         <xsl:value-of select="local-name()" />
         <xsl:value-of select="." />
       </xsl:for-each>
     </xsl:for-each>
   </xsl:variable>
   
   <!-- process 2nd list -->
   <xsl:variable name="m" select="list2" />
   
   <xsl:variable name="y">
     <xsl:for-each select="list2/*">          
       <temp pos="{position()}">
         <xsl:value-of select="local-name()" />
         <xsl:for-each select="@*">
           <xsl:value-of select="local-name()" />
           <xsl:value-of select="." />
         </xsl:for-each>
       </temp>
     </xsl:for-each>
   </xsl:variable>
   
   <xsl:variable name="listB">
     <xsl:for-each select="msxsl:node-set($y)/temp[generate-id() = 
generate-id(key('dup', .)[1])]">
       <xsl:sort select="." />
       <xsl:variable name="pos" select="@pos" />
       <xsl:copy-of select="$m/*[position() = $pos]" />
     </xsl:for-each>
   </xsl:variable>
   
   <xsl:variable name="hash2">
     <xsl:for-each select="msxsl:node-set($listB)/*">
       <xsl:value-of select="local-name()" />
       <xsl:for-each select="@*">
         <xsl:value-of select="local-name()" />
         <xsl:value-of select="." />
       </xsl:for-each>
     </xsl:for-each>
   </xsl:variable>
   
   <!-- compare list1 and list2 -->
   <xsl:choose>
     <xsl:when test="$hash1 = $hash2">
       <xsl:text>NO CHANGES WERE DETECTED</xsl:text>
     </xsl:when>
     <xsl:otherwise>
       <xsl:text>CHANGES WERE DETECTED</xsl:text>
     </xsl:otherwise>
   </xsl:choose>
   
</xsl:template>

</xsl:stylesheet>

Regards,
Mukul

"Dmitry Nogin" wrote:

> Hi,
> 
> How can I compare two lists?
> Ordering should be ignored.
> Duplicates are allowed and should be ignored.
> 
> For example:
> 
>    <list1>
>      <item name="aaa"/>
>      <item name="bbb"/>
>    </list1>
> 
>    <list2>
>      <item name="aaa"/>
>      <item name="bbb"/>
>      <item name="ccc"/>
>    </list2>
> 
> I'd like to output something like this:
> 
>   CHANGES WERE DETECTED
> 
> or
> 
>   NO CHANGES  WERE DETECTED
> 
> Are there any simple approach?
> 
> 
>     Thanks a lot,
>          dmitry