The realization space is
  [1   0   1   1        1     x1 - 1   0              x1^2 - 3*x1 + 3        0        1    1]
  [0   1   1   1   x1 - 1   2*x1 - 3   0                            0   x1 - 1   x1 - 1   x1]
  [0   0   0   1   x1 - 1     x1 - 1   1   x1^2 - 2*x1*x2 - x1 + 3*x2       x2       x2   x2]
in the multivariate polynomial ring in 2 variables over ZZ
avoiding the zero loci of the polynomials
RingElem[x2, x2 - 1, x1 - x2 - 1, x1 - 1, x1, x1^2 - x1*x2 - 2*x1 + 2*x2 + 1, x1^2 - 2*x1*x2 - x1 + 3*x2, x1 - 2, x1^2 - 3*x1 + 3, x1 - x2, x1^2 - 2*x1*x2 - 2*x1 + 3*x2 + 1, x1^2 - x1*x2 - 2*x1 + 3*x2, x1 - 3, 2*x1 - 3, x1^2*x2 - 2*x1^2 - 2*x1*x2 + 5*x1 - 3, x1^3 - 5*x1^2 + 2*x1*x2 + 7*x1 - 3*x2 - 3]