<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
    <defs>
        <pattern id="cycle2" patternUnits="userSpaceOnUse" patternContentUnits="userSpaceOnUse" x="20" y="20" width="50" height="30">
            <rect x="0" y="0" width="50" height="30" fill="blue" stroke="green"/>
        </pattern>

        <pattern id="cycle1" xlink:href="#cycle2"/>
    </defs>

    <rect fill="url(#cycle1) green" width="100px" height="100px" />
    <text x="10" y="150">The square above should show a pattern now that fill fallback is supported.</text>
</svg>