Omission in EBNF grammar for content MathML

Hi,

Saw that the EBNF rules specified in appendix B of the standard (any 
version) do not include a rule that produces a <partialdiff> with a 
<degree> (outside of <bvar>). I guess the rule for diffop should be amended to:
_diffop := diff | (partialdiff degree?)

Will write again if I find something else - I am writing a CFG parser based 
on these rules.

Reagrds
Amit