Basic test of the handling of bad entities
<!DOCTYPE math PUBLIC "-//W3C//DTD XHTML 1.1 plus MathML 2.0//EN" "http://www.w3.org/Math/DTD/mathml2/xhtml-math11-f.dtd">
<math xmlns="http://www.w3.org/1998/Math/MathML">
<mn>&foo;</mn>
</math>
Author: Dave Doyle, Design Science
