The realization space is
  [1   1   0            -x1^2 - x1 + 1   0   1   1        0            -x1^2 - x1 + 1         1      x1 - 1]
  [0   1   1   -x1^3 + x1^2 - 2*x1 + 1   0   0   1   x1 - 1   -x1^3 + x1^2 - 2*x1 + 1        x1   x1^2 - x1]
  [0   0   0                         0   1   1   1      -x1           x1^3 - 2*x1 + 1   -x1 + 1       -x1^2]
in the multivariate polynomial ring in 1 variable over ZZ
within the vanishing set of the ideal
Ideal (-2*x1^11 + 9*x1^10 - 12*x1^9 + 2*x1^8 + 23*x1^7 - 53*x1^6 + 57*x1^5 - 32*x1^4 + 9*x1^3 - x1^2)
avoiding the zero loci of the polynomials
RingElem[2*x1 - 1, x1, x1 - 1, x1^3 - x1^2 + 2*x1 - 1, x1^2 + x1 - 1, x1^3 - 2*x1^2 + 3*x1 - 1, x1^3 - 2*x1^2 - x1 + 1, x1^2 - 4*x1 + 2, x1^4 - 2*x1^3 + 2*x1^2 + x1 - 1]