The realization space is
  [1    1   x1 - 1   1   0   x1 - 1   0   2*x1^2 - x1*x2 - 2*x1 + x2          2*x1^2 - x1*x2 - 2*x1 + x2                                      0             2*x1^2 - x1*x2 - 2*x1 + x2]
  [1   x1        0   0   1      -x1   0   2*x1^2 - x1*x2 - 2*x1 + x2   2*x1^3 - x1^2*x2 - 2*x1^2 + x1*x2   2*x1^2*x2 - x1*x2^2 - 2*x1*x2 + x2^2   2*x1^2*x2 - x1*x2^2 - 2*x1*x2 + x2^2]
  [0    1       -1   0   0       -1   1                       x2 - 1                          x1*x2 - x1                             x1*x2 - x1                             x1*x2 - x1]
in the multivariate polynomial ring in 2 variables over ZZ
avoiding the zero loci of the polynomials
RingElem[x2 - 1, x1, x1 - x2, x1*x2 + x1 - x2, 2*x1 - 1, x2, 2*x1 - x2, x1 - x2 - 1, x1^2*x2 - x1^2 - x1*x2^2 - x1*x2 + x2^2, x1^2*x2 - x1^2 - 2*x1*x2 + x2, x1*x2 + x1 - 1, 2*x1^2 - x1*x2^2 - x1*x2 - x1 + x2^2, x1*x2 + x1 - x2^2, x1 - 1, 2*x1^3 - 3*x1^2*x2 - 2*x1^2 + 3*x1*x2 + x1 - x2, 2*x1^2 - x1*x2 - 2*x1 + 1]