'missed' step?

I'm using calabash, unzip a file then I want to pretty print it, using
xslt to indent it.

<p:pipeline xmlns:p="http://www.w3.org/ns/xproc"
	     xmlns:c="http://www.w3.org/ns/xproc-step"
	     xmlns:cx="http://xmlcalabash.com/ns/extensions"
	     xmlns:pxp="http://exproc.org/proposed/steps"
	     exclude-inline-prefixes="pxp"
                version="1.0">

<p:declare-step type="cx:unzip" name="uz">
  <p:output port="result"/>
  <p:option name="href" required="true"/>                       <!-- anyURI -->
  <p:option name="file"/>                                       <!-- string -->
  <p:option name="content-type"/>                               <!-- string -->
</p:declare-step>



<cx:unzip  href='11620.epub' name='unravel' />

<p:xslt name='clean' version="1.0">
  <p:input port="stylesheet" >
    <p:document href="clean.xsl"/>
  </p:input>
  <p:input port="parameters">
            <p:empty/>
        </p:input>
</p:xslt>
 </p:pipeline>

The output of the pipeline is not indented, despite the stylesheet working
on that file.

Puzzled. Any suggestion please.

TIA



-- 
Dave Pawson
XSLT XSL-FO FAQ.
Docbook FAQ.
http://www.dpawson.co.uk