SQL++ in CBAS doesn't support UNION (and friends)

-- We should improve our coverage of SQL set operations sometime!

USE TinySocial;

SELECT VALUE user
FROM GleambookUsers user
WHERE user.id BETWEEN 1 AND 2
UNION
SELECT VALUE user
FROM GleambookUsers user
WHERE user.id BETWEEN 5 AND 6;

ERROR: Code: 1 "ASX1079: Compilation error: Operation UNION with set semantics is not supported. (in line 3, at column 1)"