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