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