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