<!ELEMENT string (#PCDATA)>
<!ATTLIST string xml:space (default|preserve) 'preserve'>
<!ELEMENT matrix (double,double,double,double)>
-<!ELEMENT bool (true|false)>
+<!ELEMENT bool (#PCDATA)>
<!ELEMENT charset (#PCDATA)>
<!ATTLIST charset xml:space (default|preserve) 'preserve'>
<!ELEMENT name (#PCDATA)>