p:run-040

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:run>
      <p:with-input>
         <p:inline>
            <p:declare-step xmlns:fn="http://www.w3.org/2005/xpath-functions" xmlns:xs="http://www.w3.org/2001/XMLSchema" version="3.0">
               <p:output port="result"/>
               <p:option name="opt" as="xs:string" required="true"/>
               <p:identity>
                  <p:with-input>
                     <result>{fn:empty($opt)}</result>
                  </p:with-input>
               </p:identity>
            </p:declare-step>
         </p:inline>
      </p:with-input>
      <p:output port="result"/>
   </p:run>
</p:declare-step>