Suppose that you run a Ouija board factory. Ouija board manufacturing is a perfectly competitive industry with three inputs: Workers (L), Machinery (K), and a portal to the spirit world (Z). No Ouija boards can be produced without opening a portal to the spirit world, but it is entirely unnecessary to have more than one portal opened in order to manufacture Ouija boards. Thus the production technology of a Ouija board factory can be written as: