<svg xmlns='http://www.w3.org/2000/svg'>
  <rect width='100' height='100' fill='red' />
  <rect x='-100' width='100' height='100' fill='red'>
    <set attributeName='x' to='0' dur='3s' />
    <set attributeName='fill' to='green' dur='3s' />
  </rect>
  <text x='10' y='120'>
    There should be a 100x100 green rect at 0,0.
  </text>  
</svg>