The realization space is
  [1   1   0   2*x1 - 1   0   1   1            0      2*x1 - 1   2*x1 - 1    1]
  [0   1   1    -x1 + 1   0   0   1     2*x1 - 1       -x1 + 1         x1   x1]
  [0   0   0          0   1   1   1   2*x1^2 - 1   2*x1^2 - x1     x1 - 1   x1]
in the multivariate polynomial ring in 1 variable over ZZ
within the vanishing set of the ideal
Ideal (2*x1^3 - 2*x1^2 + 2*x1 - 1)
avoiding the zero loci of the polynomials
RingElem[x1, x1 - 1, 2*x1 - 1, 2*x1^2 - 2*x1 + 1, 2, 4*x1^5 - 12*x1^4 + 16*x1^3 - 10*x1^2 + 4*x1 - 1, 2*x1^3 - 4*x1^2 + 4*x1 - 1, 2*x1^3 - 6*x1^2 + 8*x1 - 3, 4*x1^5 - 16*x1^4 + 24*x1^3 - 20*x1^2 + 8*x1 - 1, 2*x1^3 - 4*x1^2 + 5*x1 - 2, 2*x1^2 - 1, 2*x1^3 - 6*x1^2 + 4*x1 - 1, 2*x1^3 - 2*x1 + 1, 4*x1^6 - 12*x1^5 + 12*x1^4 - 6*x1^2 + 4*x1 - 1, 2*x1^3 - 4*x1^2 + 1, 4*x1^5 - 8*x1^4 + 4*x1^3 - 2*x1 + 1, 2*x1^3 + x1 - 1, 4*x1^5 - 12*x1^4 + 14*x1^3 - 4*x1^2 - 2*x1 + 1, 4*x1^5 - 12*x1^4 + 10*x1^3 + 6*x1^2 - 10*x1 + 3, 4*x1^5 - 8*x1^4 + 2*x1^3 + 8*x1^2 - 6*x1 + 1, 2*x1^2 - 4*x1 + 1, 2*x1^4 - 2*x1^3 + 2*x1 - 1, 4*x1^6 - 12*x1^5 + 14*x1^4 - 8*x1^3 - 2*x1^2 + 4*x1 - 1]