The realization space is
  [0   1   1   0   0   1         x1*x2 - x1 - x2^2 + x2   -2*x1*x2 + x1 + x2^2 - x2 - 1   -2*x1*x2 + x1 + x2^2 - x2 - 1          x1*x2 - x1 - x2^2 + x2    1]
  [1   1   0   1   0   0   -x1*x2^2 + x1*x2 - x2^2 - x2                        -x1 + x2                        -x1 + x2    -x1*x2^2 + x1*x2 - x2^2 - x2   x1]
  [1   1   0   0   1   1                              0    -x1*x2^2 + x1*x2 - x2^2 - x2                   -x1*x2^2 - x2   x1*x2^2 - x1*x2 - x2^3 + x2^2   x2]
in the multivariate polynomial ring in 2 variables over ZZ
within the vanishing set of the ideal
Ideal (x1^2*x2 - x1^2 + x1*x2 + x2)
avoiding the zero loci of the polynomials
RingElem[x1*x2 - x1 + x2 + 1, x1, x2, x2 - 1, x1^3*x2^2 - x1^3 + 2*x1^2*x2 - x1*x2^2 + x1*x2 + x2^3 - x2^2, x1^3*x2 - x1^3 + x1^2*x2 - x1^2 + 3*x1*x2 - x1 - x2^2 + x2, x1*x2 - x1 + x2, x1^2 + 1, x1^2*x2^2 - x1^2*x2 + x1*x2^2 - x1 + x2^2 + x2, x1^2*x2 - x1^2 + x1*x2 - x1 + 2*x2, x1*x2^2 - x1 + 2*x2, x1^2*x2 - x1^2 + 2*x1*x2 - x2^2 + x2, x1^3*x2^2 - x1^3 + x1^2*x2^2 + x1^2 + x1*x2^2 - x1*x2 + x2^2 - x2, x1^3*x2^2 - x1^3 - x1^2*x2^3 + 2*x1^2*x2^2 + x1^2*x2 - x1*x2^3 + x1*x2^2 - x2^3 + x2^2, x1^2*x2^2 - x1^2 + x1*x2 + x1 + x2^2 - x2, x1*x2 + 1, x1 - x2 + 1, x1 - 1, x1 - x2, x1^3*x2^2 - x1^3 + x1^2*x2 + x1^2 + 2*x1*x2^2 - 2*x1*x2 - x2^3 + x2^2, x1^2*x2^3 - x1^2*x2^2 - x1^2*x2 + x1^2 + x1*x2^3 + x1*x2^2 - x1*x2 - x1 + x2^3 + x2, x1^3*x2^2 - x1^3 - x1^2*x2^2 + 4*x1^2*x2 - x1^2 + x1*x2^3 - 3*x1*x2^2 + 2*x1*x2 + x2^3 - x2^2, x1^4*x2^4 - 2*x1^4*x2^2 + x1^4 - x1^3*x2^4 + 5*x1^3*x2^3 + x1^3*x2^2 - 5*x1^3*x2 + x1^2*x2^5 - 2*x1^2*x2^4 - x1^2*x2^3 + 6*x1^2*x2^2 + x1*x2^5 - x1*x2^4 - x1*x2^3 + x1*x2^2 + x2^5 - x2^3, x1^4*x2^4 - 2*x1^4*x2^2 + x1^4 - x1^3*x2^4 + 6*x1^3*x2^3 - 6*x1^3*x2 + x1^3 + x1^2*x2^5 - 3*x1^2*x2^4 + 8*x1^2*x2^2 - x1^2*x2 - x1^2 + x1*x2^5 - x1*x2^4 - x1*x2^3 - x1*x2^2 + 2*x1*x2 + x2^5 - x2^4 + x2^3 - x2^2, x1^2*x2^2 - x1^2 - x1*x2^2 + 4*x1*x2 - x1 + x2^3 - 2*x2^2 + x2, x1^2*x2^2 - x1^2 - x1*x2^2 + 3*x1*x2 + x2^3 - x2^2, x1^2*x2^3 - x1^2*x2^2 - x1^2*x2 + x1^2 + x1*x2^3 + x1*x2^2 - 2*x1*x2 + x2^3 + x2^2, x1^3*x2^3 - x1^3*x2^2 - x1^3*x2 + x1^3 + x1^2*x2^3 + 2*x1^2*x2^2 - 4*x1^2*x2 + x1^2 + 4*x1*x2^2 - 2*x1*x2 - x2^3 + x2^2, x1*x2 + x1 - x2 + 1, x1^3*x2^3 - x1^3*x2 + x1^2*x2^2 + 2*x1^2*x2 - x1^2 + x1*x2^3 - 3*x1*x2^2 + 2*x1*x2 + x2^3 - x2^2]