Function.xml

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<multiply>
    <leftFunc xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="Cos">
        <subFunction xsi:type="Sin">
            <subFunction xsi:type="X"/>
        </subFunction>
    </leftFunc>
    <rightFunc xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="Cos">
        <subFunction xsi:type="Sin">
            <subFunction xsi:type="X"/>
        </subFunction>
    </rightFunc>
</multiply>