Aggregates test case

SPARQL 1.1 Query Language Grammar enables to write select expressions 
with aggregates on composite expression, e.g.

select (sum(?x + ?y) as ?sum) where

and select expressions with composite expression on aggregates, e.g.

select (count(?x) + count(?y) as ?count) where

However, the aggregates test case does not contain any such example. If 
these expressions are correct, it may be useful to add such test cases.



Best regards,

Olivier