A library system, eligible for funds under this article, may consist of the following systems:
(a) A cooperative library system that, as of the effective date of this act, was designated a system under the Public Library Services Act of 1963.
(b) A library system in which two or more systems consolidate to form a library system.
(c) A library system that is formed by adding independent public library jurisdictions to an existing system.
(d) A library system formed by any combination of the above.