eja: add a randomly-failing test to the TODO.

[sage.d.git] / mjo / eja / TODO

diff --git a/mjo/eja/TODO b/mjo/eja/TODO
index 280811e41761ed62d61a7b54886e88b7795b3d7b..f34fc34701a214afd3d086a675844b44619e5d9a 100644 (file)
--- a/mjo/eja/TODO
+++ b/mjo/eja/TODO
@@ -19,7 +19,8 @@ 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
 6. Instead of storing a basis multiplication matrix, just make
    product_on_basis() a cached method and manually cache its
    entries. The cython cached method lookup should be faster than a
-   python-based matrix lookup anyway.
+   python-based matrix lookup anyway. NOTE: we should still be able
+   to recompute the table somehow. Is this worth it?
 
 7. What the ever-loving fuck is this shit?
 
@@ -27,3 +28,19 @@ 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
        sage: e0 = O.monomial(0)
        sage: e0*[[[[]]]]
        [[[[]]]]*e0
+
+8. In fact, could my octonion matrix algebra be generalized for any
+   algebra of matrices over the reals whose entries are not real? Then
+   we wouldn't need real embeddings at all. They might even be fricking
+   vector spaces if I did that...
+
+9. Add HurwitzMatrixAlgebra subclass between MatrixAlgebra and
+   OctonionMatrixAlgebra.
+
+10. Every once in a long while, the test
+
+        sage: set_random_seed()
+        sage: x = random_eja().random_element()
+        sage: x.is_invertible() == (x.det() != 0)
+
+    in eja_element.py returns False.