init do
    `alter table comments add constraint users_fk foreign key(user_id) references users(id)`
    `insert into users(id) values (1)`
end

process do
    transaction tx1 read_committed do
        `insert into comments(id, user_id) values (1, 1)`
    end
end

process do
    transaction tx2 read_committed do
        `delete from users where id = 1`
    end
end

property eventually(`select count(*) from users` = 0 and `select count(*) from comments` = 0)