How to find a non-zero point of a non-zero polynomial of low degree?
If ​ (ceil(degree/n))+1 ​ is "large", then there doesn't actually need to be such an X$\hspace{.02 in}$'.

$\Bigg(\hspace{-0.08 in}$The polynomial can be $\;\;\; \displaystyle\prod_{i\hspace{.02 in}\in \hspace{.02 in}\text{coordinates}} \: \left(\displaystyle\prod_{c\hspace{.02 in}\in (\mathbb{F}\hspace{.03 in}-\{0\})} (x_{\hspace{.02 in}i}-c)\hspace{-0.07 in}\right) \;\;\;$ and X can be the origin.$\hspace{-0.08 in}\Bigg)$

If "large" means larger than 1 plus [the minimum over the variables of the degree in that variable], then there's a uniform NC$^0$ algorithm that will, with no access to the polynomial, with neither

bit operations nor field operations nor equality tests on field elements ($\hspace{.03 in}$just copying them and

moving them around), output a polynomial-length list of elements of $\mathbb{F}^n$ such that at least one

of those elements is such an X'. ​ (When B is an upper bound on the bracketed expression from

the previous sentence, the algorithm will have B+2 distinct hard-coded field elements and output the ​ n$\cdot$(B+2) ​ results of replacing one of X's coordinates with one of the B+2 field elements.)

Thus, you need to either consider fields of "intermediate" size, or allow polynomials of

large (superpolynomial) degree. ​ (Arithmetic circuits can easily have exponential degree.)



A problem that's closer to canonical for ​ FRP ∩ PPP ​ (and is actually obviously in PPP) is

Input: ​ ​ ​ A (circuit encoding a) function ​ f : {0,1}n+1 -> {0,1}n

and a (circuit encoding a) function ​ g : {0,1}n -> {0,1}n+1

Correct Outputs: ​ ​ ​ elements x of {0,1}n+1 such that ​ g(f(x)) ≠ x
.