eja: start adding precomputed charpoly coeffs to the TODO.

diff --git a/mjo/eja/TODO b/mjo/eja/TODO
index f0901ca91b793debc4877a8ee5a670d240fa51fc..fa05841e38f6ec6f8c51970ac4981bb2d4b2ef67 100644 (file)
--- a/mjo/eja/TODO
+++ b/mjo/eja/TODO
@@ -32,6 +32,11 @@
 
 8. Pre-cache charpoly for some small algebras?
 
+RealSymmetricEJA(4):
+
+sage: F = J.base_ring()
+sage: a0 = (1/4)*X[4]**2*X[6]**2 - (1/2)*X[2]*X[5]*X[6]**2 - (1/2)*X[3]*X[4]*X[6]*X[7] + (F(2).sqrt()/2)*X[1]*X[5]*X[6]*X[7] + (1/4)*X[3]**2*X[7]**2 - (1/2)*X[0]*X[5]*X[7]**2 + (F(2).sqrt()/2)*X[2]*X[3]*X[6]*X[8] - (1/2)*X[1]*X[4]*X[6*X[8] - (1/2)*X[1]*X[3]*X[7]*X[8] + (F(2).sqrt()/2)*X[0]*X[4]*X[7]*X[8] + (1/4)*X[1]**2*X[8]**2 - (1/2)*X[0]*X[2]*X[8]**2 - (1/2)*X[2]*X[3]**2*X[9] + (F(2).sqrt()/2)*X[1]*X[3]*X[4]*X[9] - (1/2)*X[0]*X[4]**2*X[9] - (1/2)*X[1]**2*X[5]*X[9] + X[0]*X[2]*X[5]*X[9]
+
 9. Compute the scalar in the general natural_inner_product() for
    matrices, so no overrides are necessary.