Static variables/option 046

The pipeline

        <p:declare-step xmlns:p="http://www.w3.org/ns/xproc" name="main" version="3.0">
            <p:output port="result"/>
            <p:variable static="true" name="static-option" select="14"/>
            
            <p:declare-step type="dummy:test">
                <p:output port="result"/>
                <p:variable name="static-option" select="15"/>
            
                <p:identity>
                    <p:with-input><doc xmlns=""/></p:with-input>
                </p:identity>
            </p:declare-step>
            
            <dummy:test xmlns:dummy="http://dummy"/>
        </p:declare-step>