  In [1], systems of weakening of intuitionistic negation logic called Z_n and
CZ_n were developed in the spirit of da Costa's approach(c.f. [2]) by
preserving, differently from da Costa, its fundamental properties:
antitonicity, inversion and additivity for distributive lattices. However,
according to [3], those systems turned out to be not paraconsistent but
extensions of intuitionistic logic. Taking into account of this result, we
shall here make some observations on the modified systems of Z_n and CZ_n, that
are paraconsistent as well.
