Creating multiple Rules for on update

I have a view joining two tables with a (1 to 1) relationship. I am trying to create two update
rules (1 rule for each table in the view). To accomplish this I am trying (unsuccessfully) to use
the where condition syntax of the update rules.

Basically, I only want to update a table if the columns related to its tuple are altered. If
possible, I don't want to update/touch a tuple from a table who's data remains unchanged.
However, the where conditions that I am using to make this distinction are giving the following
error:

"ERROR: cannot update a view"
"HINT: You need an unconditional ON UPDATE DO INSTEAD rule."

Ofcourse, if my understanding of the use of the rule's WHERE condition is why off base, I would be
enteresting in knowing the proper way it should be used.

Here are my sample table, view, and rule definitions: <rule are at the bottom>

CREATE SEQUENCE public.person_seq
INCREMENT BY 1
START WITH 1
;

CREATE TABLE public.person
(
id integer primary key not null
default nextval('public.person_seq'),
name varchar(30) unique not null
)
;

ALTER SEQUENCE public.person_seq OWNED BY public.person.id;

CREATE TABLE public.husband
(
id integer primary key
references person(id),
tiesize integer not null
)
;

CREATE OR REPLACE VIEW public.vhusband (id, name, tiesize) AS
SELECT
A.id, A.name, B.tiesize
FROM
public.person as A
INNER JOIN
public.husband as B
ON
A.id = B.ID
;

CREATE OR REPLACE RULE
vhusband_update_person
AS ON UPDATE TO
public.vhusband
WHERE

-- this is where I am trying to constrain which table
-- gets updated. Since name in only in the person table.
(NEW.name)<>(OLD.name)

DO INSTEAD
(
UPDATE
public.person
SET
name = NEW.name
WHERE
id = OLD.id
)
;

CREATE OR REPLACE RULE
vhusband_update_husband
AS ON UPDATE TO
public.vhusband
WHERE

-- this is where I am trying to constrain which table
-- gets updated. Since tiesize in only in the husband table.
(NEW.tiesize)<>(OLD.tiesize)
DO INSTEAD
(
UPDATE
public.husband
SET
tiesize = NEW.tiesize
WHERE
id = OLD.id
)
;

Regards,

Richard Broersma Jr.