restart; with(LinearAlgebra): # Define indeterminates QParam := [q1,q2,q3,q4,q5,q6]: PParam := Matrix([[p1],[p2],[p3],[p4],[p5],[p6],[p7]]): # Special Fourier parameterization and inverse F := Matrix([[1,1,1,1,1,1,1], [1,-1/3,-1/3,1,1,-1/3,1], [1,1/3,-1/3,-1,-1,1/3,1], [1,-1,1,-1,-1,-1,1], [1,1/2,0,-1/2,1/2,-1/2,-1], [1,-1/2,0,1/2,-1/2,1/2,-1]]): FI := Matrix([ [1/16,3/16,3/16,1/16,1/4,1/4], [3/16,-3/16,3/16,-3/16,3/8,-3/8], [3/8,-3/8,-3/8,3/8,0,0], [1/16,3/16,-3/16,-1/16,-1/8,1/8], [1/16,3/16,-3/16,-1/16,1/8,-1/8], [3/16,-3/16,3/16,-3/16,-3/8,3/8], [1/16,3/16,3/16,1/16,-1/4,-1/4] ]): # List of polynomial parametrizations P0 := [ b0^2*d0^3*g0^5+b0^2*d0^3*g1^5+2*b0^2*d0^2*d1*g0^4*g1+b0^2*d0^2*d1*g0^3*g1^2+b0^2*d0^2*d1*g0^2*g1^3+2*b0^2*d0^2*d1*g0*g1^4+2*b0^2*d0*d1^2*g0^4*g1+b0^2*d0*d1^2*g0^3*g1^2+b0^2*d0*d1^2*g0^2*g1^3+2*b0^2*d0*d1^2*g0*g1^4+b0^2*d1^3*g0^5+b0^2*d1^3*g1^5+2*b0*b1*d0^3*g0^4*g1+2*b0*b1*d0^3*g0*g1^4+2*b0*b1*d0^2*d1*g0^5+2*b0*b1*d0^2*d1*g0^4*g1+2*b0*b1*d0^2*d1*g0^3*g1^2+2*b0*b1*d0^2*d1*g0^2*g1^3+2*b0*b1*d0^2*d1*g0*g1^4+2*b0*b1*d0^2*d1*g1^5+2*b0*b1*d0*d1^2*g0^5+2*b0*b1*d0*d1^2*g0^4*g1+2*b0*b1*d0*d1^2*g0^3*g1^2+2*b0*b1*d0*d1^2*g0^2*g1^3+2*b0*b1*d0*d1^2*g0*g1^4+2*b0*b1*d0*d1^2*g1^5+2*b0*b1*d1^3*g0^4*g1+2*b0*b1*d1^3*g0*g1^4+b1^2*d0^3*g0^5+b1^2*d0^3*g1^5+2*b1^2*d0^2*d1*g0^4*g1+b1^2*d0^2*d1*g0^3*g1^2+b1^2*d0^2*d1*g0^2*g1^3+2*b1^2*d0^2*d1*g0*g1^4+2*b1^2*d0*d1^2*g0^4*g1+b1^2*d0*d1^2*g0^3*g1^2+b1^2*d0*d1^2*g0^2*g1^3+2*b1^2*d0*d1^2*g0*g1^4+b1^2*d1^3*g0^5+b1^2*d1^3*g1^5, 3*b0^2*d0^3*g0^4*g1+3*b0^2*d0^3*g0*g1^4+9*b0^2*d0^2*d1*g0^3*g1^2+9*b0^2*d0^2*d1*g0^2*g1^3+9*b0^2*d0*d1^2*g0^3*g1^2+9*b0^2*d0*d1^2*g0^2*g1^3+3*b0^2*d1^3*g0^4*g1+3*b0^2*d1^3*g0*g1^4+6*b0*b1*d0^3*g0^3*g1^2+6*b0*b1*d0^3*g0^2*g1^3+6*b0*b1*d0^2*d1*g0^4*g1+12*b0*b1*d0^2*d1*g0^3*g1^2+12*b0*b1*d0^2*d1*g0^2*g1^3+6*b0*b1*d0^2*d1*g0*g1^4+6*b0*b1*d0*d1^2*g0^4*g1+12*b0*b1*d0*d1^2*g0^3*g1^2+12*b0*b1*d0*d1^2*g0^2*g1^3+6*b0*b1*d0*d1^2*g0*g1^4+6*b0*b1*d1^3*g0^3*g1^2+6*b0*b1*d1^3*g0^2*g1^3+3*b1^2*d0^3*g0^4*g1+3*b1^2*d0^3*g0*g1^4+9*b1^2*d0^2*d1*g0^3*g1^2+9*b1^2*d0^2*d1*g0^2*g1^3+9*b1^2*d0*d1^2*g0^3*g1^2+9*b1^2*d0*d1^2*g0^2*g1^3+3*b1^2*d1^3*g0^4*g1+3*b1^2*d1^3*g0*g1^4, 6*b0^2*d0^3*g0^3*g1^2+6*b0^2*d0^3*g0^2*g1^3+6*b0^2*d0^2*d1*g0^4*g1+12*b0^2*d0^2*d1*g0^3*g1^2+12*b0^2*d0^2*d1*g0^2*g1^3+6*b0^2*d0^2*d1*g0*g1^4+6*b0^2*d0*d1^2*g0^4*g1+12*b0^2*d0*d1^2*g0^3*g1^2+12*b0^2*d0*d1^2*g0^2*g1^3+6*b0^2*d0*d1^2*g0*g1^4+6*b0^2*d1^3*g0^3*g1^2+6*b0^2*d1^3*g0^2*g1^3+12*b0*b1*d0^3*g0^3*g1^2+12*b0*b1*d0^3*g0^2*g1^3+12*b0*b1*d0^2*d1*g0^4*g1+24*b0*b1*d0^2*d1*g0^3*g1^2+24*b0*b1*d0^2*d1*g0^2*g1^3+12*b0*b1*d0^2*d1*g0*g1^4+12*b0*b1*d0*d1^2*g0^4*g1+24*b0*b1*d0*d1^2*g0^3*g1^2+24*b0*b1*d0*d1^2*g0^2*g1^3+12*b0*b1*d0*d1^2*g0*g1^4+12*b0*b1*d1^3*g0^3*g1^2+12*b0*b1*d1^3*g0^2*g1^3+6*b1^2*d0^3*g0^3*g1^2+6*b1^2*d0^3*g0^2*g1^3+6*b1^2*d0^2*d1*g0^4*g1+12*b1^2*d0^2*d1*g0^3*g1^2+12*b1^2*d0^2*d1*g0^2*g1^3+6*b1^2*d0^2*d1*g0*g1^4+6*b1^2*d0*d1^2*g0^4*g1+12*b1^2*d0*d1^2*g0^3*g1^2+12*b1^2*d0*d1^2*g0^2*g1^3+6*b1^2*d0*d1^2*g0*g1^4+6*b1^2*d1^3*g0^3*g1^2+6*b1^2*d1^3*g0^2*g1^3, b0^2*d0^3*g0^3*g1^2+b0^2*d0^3*g0^2*g1^3+b0^2*d0^2*d1*g0^5+2*b0^2*d0^2*d1*g0^4*g1+2*b0^2*d0^2*d1*g0*g1^4+b0^2*d0^2*d1*g1^5+b0^2*d0*d1^2*g0^5+2*b0^2*d0*d1^2*g0^4*g1+2*b0^2*d0*d1^2*g0*g1^4+b0^2*d0*d1^2*g1^5+b0^2*d1^3*g0^3*g1^2+b0^2*d1^3*g0^2*g1^3+2*b0*b1*d0^3*g0^4*g1+2*b0*b1*d0^3*g0*g1^4+2*b0*b1*d0^2*d1*g0^5+2*b0*b1*d0^2*d1*g0^4*g1+2*b0*b1*d0^2*d1*g0^3*g1^2+2*b0*b1*d0^2*d1*g0^2*g1^3+2*b0*b1*d0^2*d1*g0*g1^4+2*b0*b1*d0^2*d1*g1^5+2*b0*b1*d0*d1^2*g0^5+2*b0*b1*d0*d1^2*g0^4*g1+2*b0*b1*d0*d1^2*g0^3*g1^2+2*b0*b1*d0*d1^2*g0^2*g1^3+2*b0*b1*d0*d1^2*g0*g1^4+2*b0*b1*d0*d1^2*g1^5+2*b0*b1*d1^3*g0^4*g1+2*b0*b1*d1^3*g0*g1^4+b1^2*d0^3*g0^3*g1^2+b1^2*d0^3*g0^2*g1^3+b1^2*d0^2*d1*g0^5+2*b1^2*d0^2*d1*g0^4*g1+2*b1^2*d0^2*d1*g0*g1^4+b1^2*d0^2*d1*g1^5+b1^2*d0*d1^2*g0^5+2*b1^2*d0*d1^2*g0^4*g1+2*b1^2*d0*d1^2*g0*g1^4+b1^2*d0*d1^2*g1^5+b1^2*d1^3*g0^3*g1^2+b1^2*d1^3*g0^2*g1^3, b0^2*d0^3*g0^4*g1+b0^2*d0^3*g0*g1^4+b0^2*d0^2*d1*g0^5+b0^2*d0^2*d1*g0^4*g1+b0^2*d0^2*d1*g0^3*g1^2+b0^2*d0^2*d1*g0^2*g1^3+b0^2*d0^2*d1*g0*g1^4+b0^2*d0^2*d1*g1^5+b0^2*d0*d1^2*g0^5+b0^2*d0*d1^2*g0^4*g1+b0^2*d0*d1^2*g0^3*g1^2+b0^2*d0*d1^2*g0^2*g1^3+b0^2*d0*d1^2*g0*g1^4+b0^2*d0*d1^2*g1^5+b0^2*d1^3*g0^4*g1+b0^2*d1^3*g0*g1^4+2*b0*b1*d0^3*g0^3*g1^2+2*b0*b1*d0^3*g0^2*g1^3+2*b0*b1*d0^2*d1*g0^5+4*b0*b1*d0^2*d1*g0^4*g1+4*b0*b1*d0^2*d1*g0*g1^4+2*b0*b1*d0^2*d1*g1^5+2*b0*b1*d0*d1^2*g0^5+4*b0*b1*d0*d1^2*g0^4*g1+4*b0*b1*d0*d1^2*g0*g1^4+2*b0*b1*d0*d1^2*g1^5+2*b0*b1*d1^3*g0^3*g1^2+2*b0*b1*d1^3*g0^2*g1^3+b1^2*d0^3*g0^4*g1+b1^2*d0^3*g0*g1^4+b1^2*d0^2*d1*g0^5+b1^2*d0^2*d1*g0^4*g1+b1^2*d0^2*d1*g0^3*g1^2+b1^2*d0^2*d1*g0^2*g1^3+b1^2*d0^2*d1*g0*g1^4+b1^2*d0^2*d1*g1^5+b1^2*d0*d1^2*g0^5+b1^2*d0*d1^2*g0^4*g1+b1^2*d0*d1^2*g0^3*g1^2+b1^2*d0*d1^2*g0^2*g1^3+b1^2*d0*d1^2*g0*g1^4+b1^2*d0*d1^2*g1^5+b1^2*d1^3*g0^4*g1+b1^2*d1^3*g0*g1^4, 3*b0^2*d0^3*g0^3*g1^2+3*b0^2*d0^3*g0^2*g1^3+3*b0^2*d0^2*d1*g0^4*g1+6*b0^2*d0^2*d1*g0^3*g1^2+6*b0^2*d0^2*d1*g0^2*g1^3+3*b0^2*d0^2*d1*g0*g1^4+3*b0^2*d0*d1^2*g0^4*g1+6*b0^2*d0*d1^2*g0^3*g1^2+6*b0^2*d0*d1^2*g0^2*g1^3+3*b0^2*d0*d1^2*g0*g1^4+3*b0^2*d1^3*g0^3*g1^2+3*b0^2*d1^3*g0^2*g1^3+6*b0*b1*d0^3*g0^4*g1+6*b0*b1*d0^3*g0*g1^4+18*b0*b1*d0^2*d1*g0^3*g1^2+18*b0*b1*d0^2*d1*g0^2*g1^3+18*b0*b1*d0*d1^2*g0^3*g1^2+18*b0*b1*d0*d1^2*g0^2*g1^3+6*b0*b1*d1^3*g0^4*g1+6*b0*b1*d1^3*g0*g1^4+3*b1^2*d0^3*g0^3*g1^2+3*b1^2*d0^3*g0^2*g1^3+3*b1^2*d0^2*d1*g0^4*g1+6*b1^2*d0^2*d1*g0^3*g1^2+6*b1^2*d0^2*d1*g0^2*g1^3+3*b1^2*d0^2*d1*g0*g1^4+3*b1^2*d0*d1^2*g0^4*g1+6*b1^2*d0*d1^2*g0^3*g1^2+6*b1^2*d0*d1^2*g0^2*g1^3+3*b1^2*d0*d1^2*g0*g1^4+3*b1^2*d1^3*g0^3*g1^2+3*b1^2*d1^3*g0^2*g1^3, b0^2*d0^3*g0^4*g1+b0^2*d0^3*g0*g1^4+b0^2*d0^2*d1*g0^5+b0^2*d0^2*d1*g0^4*g1+b0^2*d0^2*d1*g0^3*g1^2+b0^2*d0^2*d1*g0^2*g1^3+b0^2*d0^2*d1*g0*g1^4+b0^2*d0^2*d1*g1^5+b0^2*d0*d1^2*g0^5+b0^2*d0*d1^2*g0^4*g1+b0^2*d0*d1^2*g0^3*g1^2+b0^2*d0*d1^2*g0^2*g1^3+b0^2*d0*d1^2*g0*g1^4+b0^2*d0*d1^2*g1^5+b0^2*d1^3*g0^4*g1+b0^2*d1^3*g0*g1^4+2*b0*b1*d0^3*g0^5+2*b0*b1*d0^3*g1^5+4*b0*b1*d0^2*d1*g0^4*g1+2*b0*b1*d0^2*d1*g0^3*g1^2+2*b0*b1*d0^2*d1*g0^2*g1^3+4*b0*b1*d0^2*d1*g0*g1^4+4*b0*b1*d0*d1^2*g0^4*g1+2*b0*b1*d0*d1^2*g0^3*g1^2+2*b0*b1*d0*d1^2*g0^2*g1^3+4*b0*b1*d0*d1^2*g0*g1^4+2*b0*b1*d1^3*g0^5+2*b0*b1*d1^3*g1^5+b1^2*d0^3*g0^4*g1+b1^2*d0^3*g0*g1^4+b1^2*d0^2*d1*g0^5+b1^2*d0^2*d1*g0^4*g1+b1^2*d0^2*d1*g0^3*g1^2+b1^2*d0^2*d1*g0^2*g1^3+b1^2*d0^2*d1*g0*g1^4+b1^2*d0^2*d1*g1^5+b1^2*d0*d1^2*g0^5+b1^2*d0*d1^2*g0^4*g1+b1^2*d0*d1^2*g0^3*g1^2+b1^2*d0*d1^2*g0^2*g1^3+b1^2*d0*d1^2*g0*g1^4+b1^2*d0*d1^2*g1^5+b1^2*d1^3*g0^4*g1+b1^2*d1^3*g0*g1^4]: # Substitutions based on the model P := P0: P := subs(b0 = 1-b1, P): P := subs(d0 = 1-d1, P): P := subs(g0 = 1-g1, P): # Check that the polynomial parametrization lies in the probability simplex suma := 0: for i from 1 to nops(P) do suma := suma + P[i]: od: normal(expand(suma)); # Ideal of Invariants in Fourier coordinates Invariants := Matrix([ q4*q5-q3*q6, q2*q5-q1*q6, q2*q3-q1*q4]): # Ideal of Invariants in probability coordinates Fourier := MatrixMatrixMultiply(F,PParam): PInvariants := Invariants: for i from 1 to nops(QParam) do PInvariants := subs(QParam[i] = Fourier[i, 1], PInvariants): od: # Evaluation of Invariants at the polynomial/rational parametrization num := op(PInvariants[1,1..-1])[1]: for j from 1 to num do coordpoly := PInvariants[1, j]: for i from 1 to op(PParam[1..-1,1])[1] do coordpoly := subs(PParam[i, 1] = P0[i], coordpoly): od: coordpoly :=expand(coordpoly): lprint(j,coordpoly); od: