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