From b1fed66884abd74c4c2456d56389a64fe5491ab4 Mon Sep 17 00:00:00 2001
From: Michael Orlitzky <michael@orlitzky.com>
Date: Sat, 13 Mar 2021 08:42:14 -0500
Subject: [PATCH] eja: delete obsolete method override.

---
 mjo/eja/eja_algebra.py | 92 ++++++++++++++----------------------------
 1 file changed, 30 insertions(+), 62 deletions(-)

diff --git a/mjo/eja/eja_algebra.py b/mjo/eja/eja_algebra.py
index 79efd38..3361bfa 100644
--- a/mjo/eja/eja_algebra.py
+++ b/mjo/eja/eja_algebra.py
@@ -2949,6 +2949,7 @@ class CartesianProductEJA(FiniteDimensionalEJA):
 
         sage: from mjo.eja.eja_algebra import (random_eja,
         ....:                                  CartesianProductEJA,
+        ....:                                  ComplexHermitianEJA,
         ....:                                  HadamardEJA,
         ....:                                  JordanSpinEJA,
         ....:                                  RealSymmetricEJA)
@@ -3060,6 +3061,28 @@ class CartesianProductEJA(FiniteDimensionalEJA):
         | b2 || 0  | 0  | b2 |
         +----++----+----+----+
 
+    The "matrix space" of a Cartesian product always consists of
+    ordered pairs (or triples, or...) whose components are the
+    matrix spaces of its factors::
+
+            sage: J1 = HadamardEJA(2)
+            sage: J2 = ComplexHermitianEJA(2)
+            sage: J = cartesian_product([J1,J2])
+            sage: J.matrix_space()
+            The Cartesian product of (Full MatrixSpace of 2 by 1 dense
+            matrices over Algebraic Real Field, Module of 2 by 2 matrices
+            with entries in Algebraic Field over the scalar ring Algebraic
+            Real Field)
+            sage: J.one().to_matrix()[0]
+            [1]
+            [1]
+            sage: J.one().to_matrix()[1]
+            +---+---+
+            | 1 | 0 |
+            +---+---+
+            | 0 | 1 |
+            +---+---+
+
     TESTS:
 
     All factors must share the same base field::
@@ -3082,7 +3105,6 @@ class CartesianProductEJA(FiniteDimensionalEJA):
         sage: expected = J.one()             # long time
         sage: actual == expected             # long time
         True
-
     """
     def __init__(self, factors, **kwargs):
         m = len(factors)
@@ -3101,8 +3123,13 @@ class CartesianProductEJA(FiniteDimensionalEJA):
         if associative: category = category.Associative()
         category = category.join([category, category.CartesianProducts()])
 
-        # Compute my matrix space. This category isn't perfect, but
-        # is good enough for what we need to do.
+        # Compute my matrix space.  We don't simply use the
+        # ``cartesian_product()`` functor here because it acts
+        # differently on SageMath MatrixSpaces and our custom
+        # MatrixAlgebras, which are CombinatorialFreeModules. We
+        # always want the result to be represented (and indexed) as an
+        # ordered tuple. This category isn't perfect, but is good
+        # enough for what we need to do.
         MS_cat = MagmaticAlgebras(field).FiniteDimensional().WithBasis()
         MS_cat = MS_cat.Unital().CartesianProducts()
         MS_factors = tuple( J.matrix_space() for J in factors )
@@ -3196,65 +3223,6 @@ class CartesianProductEJA(FiniteDimensionalEJA):
         return cartesian_product.symbol.join("%s" % factor
                                              for factor in self._sets)
 
-    def matrix_space(self):
-        r"""
-        Return the space that our matrix basis lives in as a Cartesian
-        product.
-
-        We don't simply use the ``cartesian_product()`` functor here
-        because it acts differently on SageMath MatrixSpaces and our
-        custom MatrixAlgebras, which are CombinatorialFreeModules. We
-        always want the result to be represented (and indexed) as
-        an ordered tuple.
-
-        SETUP::
-
-            sage: from mjo.eja.eja_algebra import (ComplexHermitianEJA,
-            ....:                                  HadamardEJA,
-            ....:                                  OctonionHermitianEJA,
-            ....:                                  RealSymmetricEJA)
-
-        EXAMPLES::
-
-            sage: J1 = HadamardEJA(1)
-            sage: J2 = RealSymmetricEJA(2)
-            sage: J = cartesian_product([J1,J2])
-            sage: J.matrix_space()
-            The Cartesian product of (Full MatrixSpace of 1 by 1 dense
-            matrices over Algebraic Real Field, Full MatrixSpace of 2
-            by 2 dense matrices over Algebraic Real Field)
-
-        ::
-
-            sage: J1 = ComplexHermitianEJA(1)
-            sage: J2 = ComplexHermitianEJA(1)
-            sage: J = cartesian_product([J1,J2])
-            sage: J.one().to_matrix()[0]
-            +---+
-            | 1 |
-            +---+
-            sage: J.one().to_matrix()[1]
-            +---+
-            | 1 |
-            +---+
-
-        ::
-
-            sage: J1 = OctonionHermitianEJA(1)
-            sage: J2 = OctonionHermitianEJA(1)
-            sage: J = cartesian_product([J1,J2])
-            sage: J.one().to_matrix()[0]
-            +----+
-            | e0 |
-            +----+
-            sage: J.one().to_matrix()[1]
-            +----+
-            | e0 |
-            +----+
-
-        """
-        return super().matrix_space()
-
 
     @cached_method
     def cartesian_projection(self, i):
-- 
2.43.2