I have this SQL that is not working: ``` sqlite> select 00 AS A1, 0 AS A2, A1 + A2 AS TA; Error: no such column: A1 ``` This one works, ``` sqlite> select 00 AS A1, 0 AS A2; A1|A2 0|0 ``` I know it's easy, but I want to be able to add A1 and A2, but I can't seem to find a way. Thanks. josé