<?xml version="1.0" standalone="yes"?>

<svg width="4in" height="3in"

 xmlns = 'http://www.w3.org/Graphics/SVG/svg-19990412.dtd'>

  <desc>This example uses the switch element to provide a 

  fallback graphical representation of an equation, if 

  MathML is not supported.

  </desc>

  <!-- The <switch> element will process the first child element

       whose testing attributes evaluate to true.-->

  <switch>



    <!-- Process the MathML if the system-required attribute

         evaluates to true (i.e., the user agent supports MathML

         embedded within SVG). -->

    <foreignobject 

       system-required="http://www.w3.org/TR/REC-MathML-19980407" 

       width="100" height="50">

      <!-- MathML content goes here -->

    </foreignobject>



    <!-- Else, process the following alternate SVG.

         Note that there are no testing attributes on the <g> element.

         If no testing attributes are provided, it is as if there

         were testing attributes and they evaluated to true.-->

    <g>

      <!-- Draw a red rectangle with a text string on top. -->

      <rect style="fill: red"/>

      <text>Formula goes here</text>

    </g>



  </switch>

</svg>

