The content of Part I is nothing else than, the theory of binomial pol
ynomial sequences in infinite variables (u((1)), u((2)), u((3)),...) w
ith weight u((l)) = l. However. sometimes we are concerned with specia
lization u((l))-->(d/dn)(l)u, therefore, we call the elements in K[u((
1)), u((2)), u((3)),...] differential polynomials. As analogies of spe
cial polynomials with binomial property, we may construct special diff
erential polynomials with binomial property.