tvalue>
                                    <xf:setvalue ref="instance('number-instance')/local" value="concat(substring($binding, 4, 3), ' ', substring($binding, 7, 4))"></xf:setvalue>
                                </xf:action>
                                <xf:action if="not(normalize-space($binding))" ev:event="xforms-value-changed xforms-enabled">
                                    <xf:setvalue ref="instance('number-instance')/area"></xf:setvalue>
                                    <xf:setvalue re