<!DOCTYPE html>
<base href="http://www.example.com/">
<svg>
    <linearGradient id="paint">
        <stop stop-color="green"/>
    </linearGradient>
    <linearGradient id="inheritedPaint" href="#paint"/>
    <rect width="100" height="100" fill="url(#paint) red"/>
    <rect x="100" width="100" height="100" fill="url(#inheritedPaint) red"/>
</svg>