n=2: terms 6, deg 2 (n(n-1)=2), min deg 0 (n(n-2)=0), top == prod (Xi-Xj)^2: True, low form = 1 * e_n^{n-2}  (claimed +-(n-1)^{n-1} = 1)  0.0s
n=3: terms 38, deg 6 (n(n-1)=6), min deg 3 (n(n-2)=3), top == prod (Xi-Xj)^2: True, low form = 4 * e_n^{n-2}  (claimed +-(n-1)^{n-1} = 4)  0.0s
n=4: terms 418, deg 12 (n(n-1)=12), min deg 8 (n(n-2)=8), top == prod (Xi-Xj)^2: True, low form = -27 * e_n^{n-2}  (claimed +-(n-1)^{n-1} = 27)  0.3s
(2) D_3 (38 terms?) equals certified 2x2x2-corner F up to scalar 1: True  (terms D3=38, F=38)
(3) n=3: D_n(xi(a)) = 0 on the full grid {0..18}^2 (361 points) -> identity proved: True
(3) n=4: D_n(xi(a)) = 0 on the full grid {0..48}^3 (117649 points) -> identity proved: True
