Extended attribute grammar too complex?

Hi,

I've been looking at the extended attribute syntax and I wonder if it 
isn't just too complex.

Rules 61-66 and 68 define a somewhat elaborate construction in which 
extended attributes can be built using nested parentheses, brackets, etc.

In practice however that never seems to be used, and only rules 86-89 
(which are much simpler) ever seem to be used.

Am I missing something or could the former just be dropped?

-- 
Robin Berjon - http://berjon.com/ - @robinberjon