We can try the result for monomials, and by induction:
\( \sum_0^{a^n}f(z)\Delta z = \sum_0^{a}\sum_0^{a-1} .... \sum_0^{a-1} f(x + (t_1 + t_2 + ...+t_{n-1})a) \Delta t_1 \,\Delta t_2\,...\Delta t_{n-1} \Delta x \)
This leaves us wondering what an addition formula would be--given it could generate substitution of polynomials.
\( \sum_0^{a^n}f(z)\Delta z = \sum_0^{a}\sum_0^{a-1} .... \sum_0^{a-1} f(x + (t_1 + t_2 + ...+t_{n-1})a) \Delta t_1 \,\Delta t_2\,...\Delta t_{n-1} \Delta x \)
This leaves us wondering what an addition formula would be--given it could generate substitution of polynomials.

