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