<p:declare-step xmlns:p="http://www.w3.org/ns/xproc" xmlns:px="http://www.daisy.org/ns/pipeline/xproc" type="px:select-by-position" exclude-inline-prefixes="#all" version="1.0"> <p:input port="source" sequence="true" primary="true"/> <p:option name="position" required="true"/> <p:output port="matched" sequence="true" primary="true"/> <p:output port="not-matched" sequence="true"> <p:pipe step="split-sequence" port="not-matched"/> </p:output> <p:split-sequence name="split-sequence"> <p:with-option name="test" select="concat('position()=number(', $position,')')"> <p:empty/> </p:with-option> </p:split-sequence> </p:declare-step>