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