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

diff --git a/mjo/eja/TODO b/mjo/eja/TODO
index 2d93ffb38a772f9409ecdff4153e975cb7c02c0b..f34fc34701a214afd3d086a675844b44619e5d9a 100644 (file)
--- a/mjo/eja/TODO
+++ b/mjo/eja/TODO
@@ -36,3 +36,11 @@ 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
 
 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.