To Jonathan Robie et al..

Regarding XQuery and the so-called efficiency provided by 1-unambiguous
grammars -- after thinking about it for some time..

I believe that the efficiency provided by 1-unambiguous grammars is w.r.to
schema operations, and what we have lost is efficiency for further data
operations on the result of one operation. I would conjecture that the
loss of efficiency will outweigh any gains by a huge margin.. this loss of
efficiency will reflect in normal day to day operations, which more than
80% of the people will require.

The above is again a conjecture at this point of time, and I will try to
prove it.

cheers and regards - murali.

note: I am going to harp only on the issue of 1-unambiguity. Makoto gave
lots of other cases..