9/28/2001

Query: all suppliers in Houston or Dallas

(select [Scity = 'Houston'] (Supplier))
UNION
(select [Scity = 'Dallas'] (Supplier))

(select [Scity = 'Houston' and 'Dallas'] (Supplier));

--  Incorrect
(select [Scity = 'Houston' and SCity = 'Dallas'] (Supplier));

--  Not supported by RA interpreter.
select [Scity = 'Houston' or SCity = 'Dallas'] (Supplier);