(a) The term "revenue bonds" as used herein shall mean all bonds, notes, certificates or other instruments or evidences of indebtedness the repayment of which is secured by rents, user fees, charges, or other revenues (other than assessments for local improvements and taxes) derived from the project or improvements financed in whole or in part by such bonds, notes, certificates or other instruments or evidences of indebtedness, from the operations of any governmental unit, or from any other special fund or source other than assessments for local improvements and taxes.
(b) The term "governmental unit" as used herein shall mean the State of Arkansas; any county, municipality, or other political subdivision of the State of Arkansas; any special assessment or taxing district established under the laws of the State of Arkansas; and any agency, board, commission, or instrumentality of any of the foregoing.