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