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