EXCEPT/INTERSECT

Thomas, can you add stuff for INTERSECT and EXCEPT. I assume you know
what they do. I am just adding the grammar to the docs as needed.

I went ahead and added them, and cleaned up Cartesian. I did not know
what to do with the last UNION related to CORRESPONDING, so I just left
it, and did not add INTERSECT or EXCEPT sections to that area.

-- 
  Bruce Momjian                        |  http://www.op.net/~candle
  maillist@candle.pha.pa.us            |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026