Section 20. Credit to trust beneficiary receiving accumulation distribution

--(a) General.--A resident beneficiary  of  a  trust  whose
  city  adjusted  gross  income  includes  all  or part of an accumulation
  distribution by such trust, as defined in section six hundred sixty-five
  of the internal revenue code, shall be allowed a credit against the  tax
  otherwise  due  under  this local law for all or a proportionate part of
  any tax paid by the trust under this local law for any preceding taxable
  year which would not have been payable if the trust  had  in  fact  made
  distributions  to  its  beneficiaries  at  the  times and in the amounts
  specified in section six hundred sixty-six of the internal revenue code.
    (b) Limitation.--The credit under this section shall  not  reduce  the
  tax otherwise due from the beneficiary under this local law to an amount
  less  than  would  have been due if the accumulation distribution or his
  part thereof were excluded from his city adjusted gross income.