The realization space is
  [1   0   1       1   0   1    0   x1^2 - x1               1     1     1]
  [0   1   1   -x1^2   0   0    1   x1^2 - x1           -x1^2   -x1   -x1]
  [0   0   0       0   1   1   -1    x1^2 + 1   x1^2 - x1 + 1     1    x1]
in the multivariate polynomial ring in 1 variable over ZZ
avoiding the zero loci of the polynomials
RingElem[x1, x1 - 1, x1 + 1, x1^2 - x1 + 1, x1^2 - x1 + 2, 2*x1^2 - x1 + 1, x1^3 - 2*x1^2 - 1, x1^2 + 1, 2*x1^3 - 2*x1^2 + 3*x1 - 1, x1^4 - 2*x1^3 + x1^2 - x1 - 1]