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