For the purposes of this article, "converted
condominium" shall be a dwelling unit held in condominium form of
ownership that has previously been on an assessment roll as a dwelling
unit in other than condominium form of ownership and has not been
previously subject to the provisions of Paragraph (a) of Subdivision
1 of § 581 of the Real Property Tax Law or Paragraph (b)
of Subdivision 1 of § 339-y of the Real Property Law, as
the case may be.