<xsl:stylesheet

    version="2.0"

    xmlns:xs="http://www.w3.org/2001/XMLSchema"

    xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

    <xsl:param name="defaultedParam" select="'defParam'"/>

    <xsl:param name="overridedDefaultedParam" select="'DOESNOTAPPEAR'"/>

    <xsl:param name="implicitlyRequiredValue" as="xs:string"/>

    <xsl:template name="main">

        <xsl:sequence select="$defaultedParam,

                              $overridedDefaultedParam,

                              $implicitlyRequiredValue"/>

    </xsl:template>

</xsl:stylesheet>