The realization space is
  [1   0   1       1   0   1    0           1               1     1     1]
  [0   1   1   -x1^2   0   0    1           1           -x1^2   -x1   -x1]
  [0   0   0       0   1   1   -1   -x1^2 - 2   x1^2 - x1 + 1     1    x1]
in the multivariate polynomial ring in 1 variable over ZZ
within the vanishing set of the ideal
Ideal (x1^3 + 2*x1 - 1)
avoiding the zero loci of the polynomials
RingElem[x1, x1 - 1, x1 + 1, x1^2 - x1 + 1, x1^3 + 2*x1 + 1, x1^2 + 1, x1^2 + x1 + 2, x1^2 + 2, x1^2 - x1 + 2, x1^2 + 3, x1^4 - x1^3 + 3*x1^2 - 2*x1 + 1, x1^3 - x1^2 + 2*x1 - 1, 2*x1^2 - x1 + 3, x1^4 + 3*x1^2 + 1]