*Proper* solution for 1..* relationship?

It hit me today that a 1..* relationship can't be implemented just by a
single foreign key constraint. I must have been sleeping very deeply not
to notice this.

E.g. there is a table "list" and another table "list_item" and the
relationship can be described as "every list has at least one
list_item" (and every list_item can only be part of one list, but
this is trivial).

A "proper" solution would require:

1. A foreign key pointing from each list_item to its list

2. Another foreign key pointing from each list to one of its list_item.
But this must be a list_item that itself points to the same list, so
just a simple foreign key constraint doesn't do it.

3. When a list has more than one list_item, and you want to delete the
list_item that its list points to, you have to "re-point" the foreign
key constraint on the list first. Triggers, stored procedures...?

(4. Anything else that I've not seen?)

Is there a "straight" (and tested) solution for this in PostgreSQL, that
someone has already implemented and that can be re-used?

TIA,

Sincerely,

Wolfgang