1 L R
—————
1 1 1
1 1 2
1 1 3
1 2 1
1 2 2
1 2 3
1 3 1
1 3 2
1 3 3

SELECT * FROM

(SELECT 1 FROM dual),

(SELECT LEVEL l FROM dual CONNECT BY LEVEL <4),

(SELECT LEVEL r FROM dual CONNECT BY LEVEL <4);