<!--
     Any copyright is dedicated to the Public Domain.
     http://creativecommons.org/publicdomain/zero/1.0/
-->
<svg xmlns="http://www.w3.org/2000/svg">
  <defs>
    <filter id="blur">
      <feGaussianBlur stdDeviation="3"/>
    </filter>
  </defs>
  <!-- Background consists of a white rect and a black rect. -->
  <rect x="0" y="0" width="100" height="50" fill="#fff"/>
  <rect x="0" y="50" width="100" height="50" fill="#000"/>
  <!--
    Foreground consists of a blurred green square, blended with the background
    using the darken blend mode. Green should overwrite the white rect, while
    the black rect should show through.
  -->
  <rect x="0" y="0" width="100" height="100" fill="#0f0" filter="url(#blur)"
        style="mix-blend-mode: darken;"/>
</svg>