(a) It is the intention of this article to authorize the state to issue bonds for the purpose of refunding outstanding bonds without thereby contracting any additional indebtedness, and it shall be conditional upon the delivery of any refunding bonds that sufficient funds are held in trust to provide for the payment of the principal of, premium, if any, and interest on the bonds to be refunded. It is the further intention of this article that any amounts received by the issuance of any refunding bonds pursuant to this article be used solely for the purposes set forth in subsection (a), section five of this article and not be used for incurrence of additional debt.
(b) For all purposes of this section, bonds shall be considered to have been canceled and paid in advance of their due date or date of redemption if there shall have been deposited in trust for the benefit of holders of the bonds to be refunded:
(1) Moneys sufficient to pay when and as due all amounts of principal and interest payable on such bonds; or
(2) Direct obligations of the United States of America or the state, or obligations fully and irrevocably secured as to the payment of both principal and interest by such direct obligations the payment on which when due will provide moneys, sufficient to pay when and as due all amounts of principal and interest payable on such bonds.
(c) All such amounts shall be set aside and held in trust and irrevocably dedicated solely to the payment of such bonds, except that amounts in excess of the amounts required for the payment of the bonds so refunded may be applied to the payment of costs related to the issuance, carrying, insuring or servicing the refunding bonds, including costs of credit or market enhancement services, such as letters of credit, remarketing arrangements and similar services. Any amount deposited pursuant to this section may include amounts already held on deposit in trust for the payment of the bonds to be refunded.