The realization space is
  [1   1   0       x2 - 1   0   1   1                         0       x2 - 1         1    1]
  [0   1   1   x1*x2 - x2   0   0   1   2*x1*x2 - x1 - 2*x2 + 1   x1*x2 - x2   -x1 + 1   x2]
  [0   0   0            0   1   1   1               -x1*x2 + x1   x1*x2 - x1        x1   x2]
in the multivariate polynomial ring in 2 variables over ZZ
avoiding the zero loci of the polynomials
RingElem[x2, 2*x1 - 1, x1, 2*x2 - 1, x1 - x2, x1^2 - 3*x1*x2 + x1 + 2*x2 - 1, x1 + x2 - 1, x1 - 1, x2 - 1, 3*x1*x2 - x1 - 2*x2 + 1, 3*x1*x2 - 2*x1 - 2*x2 + 1, 3*x1*x2^2 - 3*x1*x2 + x1 - 2*x2^2 + x2, x1*x2 - 2*x2 + 1, x1^2*x2 - 4*x1*x2 + 2*x1 + 2*x2 - 1, 3*x2 - 1, 3*x1*x2 - x1 - 4*x2 + 2, 3*x1^2*x2 - x1^2 - 6*x1*x2 + 3*x1 + 2*x2 - 1]