Section 20.29. Agreement of the state

The state does hereby pledge to and
  agree with the holders of any bonds or notes of a trust that  the  state
  will  not limit or alter the rights vested in a trust by this article or
  by special law to fulfill the terms of  any  agreements  made  with  the
  holders  thereof,  or  in any way impair the rights and remedies of such
  holders until such bonds or notes together with  the  interest  thereon,
  with  interest on any unpaid installments of interest, and all costs and
  expenses in connection with any action or proceedings by or on behalf of
  such holders, are fully met and discharged. A  trust  is  authorized  to
  include this pledge and agreement of the state in any agreement with the
  holders of such bonds or notes.