eja: add a comment with a new TODO...

diff --git a/mjo/eja/eja_algebra.py b/mjo/eja/eja_algebra.py
index 9815ae48de66ebcb50fbc236d09875cc87cefb3a..55b8207ddc3f881e8d98f245bf0275bc4b947334 100644 (file)
--- a/mjo/eja/eja_algebra.py
+++ b/mjo/eja/eja_algebra.py
@@ -2762,6 +2762,18 @@ class CartesianProductEJA(CombinatorialFreeModule_CartesianProduct,
             y = self.from_vector(_mat2vec(y_mat))
             return self.cartesian_inner_product(x,y)
 
+        # Use whatever category the superclass came up with. Usually
+        # some join of the EJA and Cartesian product
+        # categories. There's no need to check the field since it
+        # already came from an EJA. Likewise the axioms are guaranteed
+        # to be satisfied. We can't orthonormalize by default because
+        # there's no way to pass "orthonormalize=False" to
+        # cartesian_product(...) when the base ring is QQ and
+        # orthonormalizing would give us irrational entries.
+        #
+        # TODO: create a separate constructor that is capable of
+        # orthonormalizing and is only used by the cartesian_product()
+        # thingy.
         FiniteDimensionalEJA.__init__(self,
                                       basis,
                                       jordan_product,