eja: add another TODO for later.

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

diff --git a/mjo/eja/TODO b/mjo/eja/TODO
index 8f9c17f11c0db462403fdf98faafded920de2839..bde3e3bb767b5fbcd9bc34971b34cf0abdaeb1dc 100644 (file)
--- a/mjo/eja/TODO
+++ b/mjo/eja/TODO
@@ -1,11 +1,7 @@
-1. Finish CartesisnProductEJA: add to_matrix(), random_instance(),
-   one()... methods. This will require rethinking what a "matrix
-   representation" and "matrix space" means for a cartesian product
-   algebra. Do we want our matrix basis to consist of ordered pairs
-   (or triples, or...)? Should the matrix_space() of the algebra
-   be the cartesian product of the factors' matrix spaces? Can
-   the FDEJA initializer be made to work on tuples, or will it
-   need to be overridden?
+1. Finish CartesianProductEJA: add to_matrix(), random_instance(),...
+   methods. I guess we should create a separate class hierarchy for
+   Cartesian products of RationalBasisEJA? That way we get fast
+   charpoly and random_instance() defined...
 
 2. Add references and start citing them.
 
@@ -24,3 +20,6 @@ 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. Profile the construction of "large" matrix algebras (like the
    15-dimensional QuaternionHermitianAlgebra(3)) to find out why
    they're so slow.
+
+7. Printing of Cartesian product subalgebrasis wrong (it prints the
+   superalgebra).