X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=mjo%2Feja%2FTODO;h=529f70fd633bf36275c63282a05614f1109a7df0;hb=d9b0659df5d8ad61f457674e009180618dffef67;hp=5307527b5285eb821f75b8e9dfa58b2d512c10a9;hpb=0378679ab4d3e52c08f126b681c20e9f9c5e9023;p=sage.d.git

diff --git a/mjo/eja/TODO b/mjo/eja/TODO
index 5307527..529f70f 100644
--- a/mjo/eja/TODO
+++ b/mjo/eja/TODO
@@ -8,4 +8,18 @@
        sage: x = random_eja().random_element()
        sage: x.is_invertible() == (x.det() != 0)
 
-   in eja_element.py returns False.
+   in eja_element.py returns False. Example:
+
+       sage: J1 = ComplexHermitianEJA(2)
+       sage: J2 = TrivialEJA()
+       sage: J = cartesian_product([J1,J2])
+       sage: x = J.from_vector(vector(QQ, [-1, -1/2, -1/2, -1/2]))
+       sage: x.is_invertible()
+       True
+       sage: x.det()
+       0
+
+4. When we take a Cartesian product involving a trivial algebra, we
+   could easily cache the identity and charpoly coefficients using
+   the nontrivial factor. On the other hand, it's nice that we can
+   test out some alternate code paths...