Issue against june 14th edition of SPARQL

Referring to

http://www.w3.org/TR/2007/CR-rdf-sparql-query-20070614/

The treatment of the ORDER BY solution processing is less than clear.

The text states:

[16]  OrderClause  ::=  'ORDER' 'BY' OrderCondition+
[17]  OrderCondition  ::=  ( 'ASC' | 'DESC' ) BrackettedExpression )
              | ( Constraint | Var )


This grammar permits *any* expression or constraint to be an order  
condition. But the text fails to give clear semantics for this.

For example, what does

.... order by ?x < 34

mean?

Perhaps the intention is something like:

eval(Q order by Exp) = sort({ (S,Exp) .. S satisfies Q })

where

(S1,Exp1) o< (S2,Exp2) iff Exp1 < Exp2

However, that would not permit a reasonable interpretation for

order by ?x < 34

(which would seem to be a weird case anyway)

Looking forward to a response

Frank McCabe

P.S. It would have been helpful if the committee adopted an OASIS- 
style policy of putting line numbers on the specification. Then I  
could quote line numbers at you.