Classes to handle parsing of content MathML. The central class is {@link com.singularsys.extensions.mathml.parser.MathMLDocumentHandler MathMLDocumentHandler} this is called by the SAX parser every time a xml start or end tag is encountered. When a tag is found the element name is looked up in a Map and the corresponding {@link com.singularsys.extensions.mathml.parser.TagHandler TagHandler} is encountered.