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