1<?xml version="1.0" standalone="yes"?>
2<svg width="4in" height="3in"
3 xmlns = 'http://www.w3.org/Graphics/SVG/svg-19990412.dtd'>
4  <desc>This example uses the switch element to provide a
5  fallback graphical representation of an equation, if
6  MathML is not supported.
7  </desc>
8  <!-- The <switch> element will process the first child element
9       whose testing attributes evaluate to true.-->
10  <switch>
11
12    <!-- Process the MathML if the system-required attribute
13         evaluates to true (i.e., the user agent supports MathML
14         embedded within SVG). -->
15    <foreignobject
16       system-required="http://www.w3.org/TR/REC-MathML-19980407"
17       width="100" height="50">
18      <!-- MathML content goes here -->
19    </foreignobject>
20
21    <!-- Else, process the following alternate SVG.
22         Note that there are no testing attributes on the <g> element.
23         If no testing attributes are provided, it is as if there
24         were testing attributes and they evaluated to true.-->
25    <g>
26      <!-- Draw a red rectangle with a text string on top. -->
27      <rect style="fill: red"/>
28      <text>Formula goes here</text>
29    </g>
30
31  </switch>
32</svg>
33