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