<?xml version="1.0"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.0//EN"
    "http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd">

<svg width="300" height="60">

<rect x="10" y="10" width="200" height="20"
      style="stroke: black; stroke-width: 2; fill: none;">

    <animate attributeName="width" attributeType="XML"
             from="200" to="20"
             begin="0s" dur="5s"
             fill="freeze"/>
</rect>

</svg>