Foreign keys: unexpected result from ALTER TABLE... ADD CONSTRAINT...

I cannot do this pair of table creations directly, because they are mutually
dependent.

create table purchased_job
(
supplier char(10) not null
references supplier (id) match full,
specification text,
del_point char(2) not null
references location (id) match full,
import_licence bool default 'f',
import_duty numeric(12,2),
terms char(3),
deliv_clear numeric(12,2),

foreign key (product, supplier) references product_supplier (product,
supplier) match full
)
inherits (job)
;

create table product_supplier
(
product char(10) not null
references purchased_job (product) match full,
supplier char(10) not null
references supplier (id) match full,

primary key (product, supplier)
)
;

so I omitted the foreign key specification from the creation of purchased_job
and tried to add it afterwards, but (after fixing a bug in gram.y) I found
that ALTER TABLE ... ADD CONSTRAINT is not yet implemented. Is there, then, any
way to create this mutual dependency?

--
Oliver Elphick Oliver(dot)Elphick(at)lfix(dot)co(dot)uk
Isle of Wight http://www.lfix.co.uk/oliver
PGP key from public servers; key ID 32B8FAA1
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