[xsl] Setting a boolean value

["Mark" <mark@xxxxxxxxxxxx>]

I have a boolean parameter and wonder if there is a "preferred" style for 
setting it to 'false':

These two work but seem indirect and verbose:
<xsl:with-param name="set-current">
       <xsl:text>false</xsl:text>
</xsl:with-param>
or
<xsl:with-param name="set-current" select="not('true')"/>

These return the error "required type ... is boolean.
<xsl:with-param name="set-current" select="''"/>
<xsl:with-param name="set-current" select="'false'"/>

And this returns the error: "An empty sequence is not allowed as the value 
of...."
<xsl:with-param name="set-current" select="false"/>

Thanks,
Mark