Can XSLT remember the occurrence of an element?

Hello list,

can XSLT remember the occurrence of an element?

e.g. XML:
<forrest:view type="xhtml">
  <forrest:contract name="meta"/>
  <forrest:hook name="container">
    <forrest:contract name="grouplogo"/>
    <forrest:contract name="searchbox"/>
    <forrest:hook name="spacer" />
    <forrest:contract name="nav"/>
    <forrest:contract name="content"/>
  </forrest:hook> 
  <forrest:contract name="searchbox"/>
  <forrest:contract name="feedback"/>
</forrest:view>

e.g. XSL:
<xsl:for-each select="forrest:view[@type=$format]//forrest:contract">
  <xi:include href="cocoon://get.contract.{$format}.{@name}"/>
</xsl:for-each>

The xsl would include now *two* times the searchbox contract, but it
*has to* be only one time. 

Any ideas how I could change the xsl to only include *one* instance of a
contract despite it is *two or more* times called? Is there a way that
xsl remembers the occurrence of an element in the above given example?

TIA

salu2
-- 
thorsten

"Together we stand, divided we fall!" 
Hey you (Pink Floyd)