p:xquery 016 (AB)

The pipeline

<p:declare-step xmlns:err="http://www.w3.org/ns/xproc-error" xmlns:p="http://www.w3.org/ns/xproc" version="3.0">
   <p:output port="result"/>
   <p:xquery parameters="map{'var' : 'not-an-integer'}">
      <p:with-input port="source">
         <doc>
            <para>A para.</para>
         </doc>
      </p:with-input>
      <p:with-input port="query">
         <p:inline content-type="text/plain">
                  declare variable $var as xs:integer external;
                  &lt;result&gt;{{$var}}&lt;/result&gt;
               </p:inline>
      </p:with-input>
   </p:xquery>
   <p:wrap-sequence wrapper="result"/>
</p:declare-step>