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