The realization space is
  [1   1   x1 - 1   0   1   0      1      1    1   0]
  [1   0      -x1   1   1   0   2*x1   2*x1    0   2]
  [0   0        0   0   1   1   2*x1     x1   x1   1]
in the multivariate polynomial ring in 1 variable over ZZ
within the vanishing set of the ideal
Ideal (8*x1^3 - 6*x1^2 + x1)
avoiding the zero loci of the polynomials
RingElem[2*x1 + 1, x1, 2*x1 - 3, 2*x1 - 1, 2, x1 - 1]