The realization space is
  [1   0   1     x2 - 1   0   1    0   1     x2 - 1    1]
  [0   1   1   -x1 + x2   0   0    1   1   -x1 + x2   x1]
  [0   0   0          0   1   1   -1   1    x1 - x2   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, x1 - x2, x1 - x2^2, x1 - 1, x1, x2, x2 - 1, x1 + x2 - 2, x1 + x2 - 1, 2, x1 - 2*x2 + 1]