DAVEfunc — Root level element
DAVEfunc :  xmlns
     fileHeader
     variableDef+
     breakpointDef*
     griddedTableDef*
     ungriddedTableDef*
     function*
     checkData?
Root element is DAVEfunc, composed of a file header element followed by one or more variable definitions and zero or more breakpoint definitions, gridded or ungridded table definitions, and function elements.
fileHeader
 | 
variableDef
 | 
breakpointDef
 | 
griddedTableDef
 | 
ungriddedTableDef
 | 
function
 | 
checkData
 | 
2011-03-25