Bug report: selects rope in tables they shouldn't

Sorry for the unformatted bug report, I can't find the bug form on
postgresql.org.

Version: 7.0

Platform: Debian Linux (woody) running kernel 2.2.14

Question:
Is it valid syntax to refer to a table when it's not in the FROM of the
select? It's producing awfully wierd output:

CREATE TABLE A (
x integer
);

CREATE TABLE B(
x integer
);

insert into A values (1);
insert into B values (2);

select * from A where B.x=2;

x
---
1
(1 row)

svan=# explain select * from A where B.x=2;
NOTICE: QUERY PLAN:

Nested Loop (cost=0.00..322.50 rows=10000 width=8)
-> Seq Scan on b (cost=0.00..22.50 rows=10 width=4)
-> Seq Scan on a (cost=0.00..20.00 rows=1000 width=4)

EXPLAIN

--
,,,
(. .)
+--ooO-(_)-Ooo------------ --- -- - - - -
| Stephen van Egmond http://bang.dhs.org/