wsdb=# CREATE TABLE xx(a int);
CREATE TABLE
wsdb=# CREATE TABLE xx1(a int);
CREATE TABLE
wsdb=# CREATE TABLE xx2(a int);
CREATE TABLE
wsdb=# CREATE RULE xxa as on insert to xx do instead insert into xx1 VALUES(NEW.a);
CREATE RULE
wsdb=# CREATE RULE xxb as on insert to xx do instead insert into xx2 VALUES(NEW.a);
CREATE RULE
wsdb=# INSERT INTO xx values( 1 );
INSERT  0   1 
wsdb=# SELECT * FROM xx;
 a 
---
( 0  rows)

wsdb=# SELECT * FROM xx1;
 a 
---
  1 
( 1  row)

wsdb=# SELECT * FROM xx2;
 a 
---
  1 
( 1  row)