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