line (a,b,c) = (0+0t, 0+1t, 0+1t), conv=kourovka, relation u_3 = s u_2
  degrees of u_n coordinates: [[0, -oo, 1, 1], [10, 10, 11, 11], [68, 68, 69, 69]] (0.0s)
  kappa = tr[x,y] = 2*t**2 - 2
  s=1: gcd degree 6, factors (4, [(t - 1, 1), (t + 1, 1), (t, 2), (t**2 - 2, 1)])
    factor g = t - 1: exact division OK; Res(g, kappa-2) = {2: 1, -1: 1}; gcd of Res(g, coords of u_2-1) = 0, of u_2+1: {2: 1}; lc(g) = 1
    factor g = t + 1: exact division OK; Res(g, kappa-2) = {2: 1, -1: 1}; gcd of Res(g, coords of u_2-1) = 0, of u_2+1: {2: 1}; lc(g) = 1
    factor g = t: exact division OK; Res(g, kappa-2) = {2: 2, -1: 1}; gcd of Res(g, coords of u_2-1) = 0, of u_2+1: {2: 1}; lc(g) = 1
    factor g = t**2 - 2: exact division OK; Res(g, kappa-2) = 0; gcd of Res(g, coords of u_2-1) = 0, of u_2+1: {2: 2}; lc(g) = 1
  s=-1: gcd degree 4, factors (2, [(2*t**4 - 4*t**2 + 1, 1)])
    factor g = 2*t**4 - 4*t**2 + 1: exact division OK; Res(g, kappa-2) = {2: 4}; gcd of Res(g, coords of u_2-1) = {2: 10}, of u_2+1: {2: 10}; lc(g) = 2
line (a,b,c) = (1+0t, 0+1t, 0+1t), conv=kourovka, relation u_4 = s u_2
  degrees of u_n coordinates: [[-oo, 0, -oo, 1], [0, 8, -oo, 9], [50, 52, 51, 53], [312, 314, 313, 315]] (0.1s)
  kappa = tr[x,y] = t**2 - 1
  s=1: gcd degree 11, factors (1, [(t - 1, 1), (t, 1), (t + 1, 1), (t**2 - 3, 1), (t**3 - t**2 - 2*t + 1, 1), (t**3 + t**2 - 2*t - 1, 1)])
    factor g = t - 1: exact division OK; Res(g, kappa-2) = {2: 1, -1: 1}; gcd of Res(g, coords of u_2-1) = 0, of u_2+1: {2: 1}; lc(g) = 1
    factor g = t: exact division OK; Res(g, kappa-2) = {3: 1, -1: 1}; gcd of Res(g, coords of u_2-1) = 0, of u_2+1: {2: 1}; lc(g) = 1
    factor g = t + 1: exact division OK; Res(g, kappa-2) = {2: 1, -1: 1}; gcd of Res(g, coords of u_2-1) = 0, of u_2+1: {2: 1}; lc(g) = 1
    factor g = t**2 - 3: exact division OK; Res(g, kappa-2) = 0; gcd of Res(g, coords of u_2-1) = 0, of u_2+1: {2: 2}; lc(g) = 1
    factor g = t**3 - t**2 - 2*t + 1: exact division OK; Res(g, kappa-2) = {}; gcd of Res(g, coords of u_2-1) = {}, of u_2+1: {}; lc(g) = 1
    factor g = t**3 + t**2 - 2*t - 1: exact division OK; Res(g, kappa-2) = {}; gcd of Res(g, coords of u_2-1) = {}, of u_2+1: {}; lc(g) = 1
  s=-1: gcd is constant 1 (no family)
