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