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