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