diff --git a/test/test_chapter13.py b/test/test_chapter13.py
index ff1ddc7d..ce6645a1 100644
--- a/test/test_chapter13.py
+++ b/test/test_chapter13.py
@@ -3,6 +3,8 @@
 from sympy import Symbol, S, sqrt
 from galgebra.ga import Ga
 
+USE_DIAGONAL_G = True
+
 
 class TestChapter13(TestCase):
 
@@ -10,44 +12,37 @@ def setUp(self):
         """
         Initialize CGA.
         """
-        g = [
-            [ 1,  0,  0,  0,  0],
-            [ 0,  1,  0,  0,  0],
-            [ 0,  0,  1,  0,  0],
-            [ 0,  0,  0,  1,  0],
-            [ 0,  0,  0,  0, -1],
-        ]
-
-        ga, e, e_1, e_2, e_3, eb = Ga.build('e e1 e2 e3 eb', g=g)
-        o = S.Half * (e + eb)
-        inf = eb - e
-
-        self.ga = ga
-        self.o = o
-        self.e_1 = e_1
-        self.e_2 = e_2
-        self.e_3 = e_3
-        self.inf = inf
-
-        """
-        # test_13_2_2 will fails with this
-        
-        g = [
-            [ 0, 0, 0, 0, -1],
-            [ 0, 1, 0, 0,  0],
-            [ 0, 0, 1, 0,  0],
-            [ 0, 0, 0, 1,  0],
-            [-1, 0, 0, 0,  0],
-        ]
+        if USE_DIAGONAL_G:
+            # This is way faster with galgebra but o and inf can't be printed...
+            g = [
+                [ 1,  0,  0,  0,  0],
+                [ 0,  1,  0,  0,  0],
+                [ 0,  0,  1,  0,  0],
+                [ 0,  0,  0,  1,  0],
+                [ 0,  0,  0,  0, -1],
+            ]
+
+            ga, e, e_1, e_2, e_3, eb = Ga.build('e e1 e2 e3 eb', g=g)
+            o = S.Half * (e + eb)
+            inf = eb - e
+
+        else:
+            g = [
+                [ 0,  0,  0,  0, -1],
+                [ 0,  1,  0,  0,  0],
+                [ 0,  0,  1,  0,  0],
+                [ 0,  0,  0,  1,  0],
+                [-1,  0,  0,  0,  0],
+            ]
+
+            ga, o, e_1, e_2, e_3, inf = Ga.build('o e1 e2 e3 inf', g=g)
 
-        ga, o, e_1, e_2, e_3, inf = Ga.build('o e1 e2 e3 inf', g=g)
         self.ga = ga
         self.o = o
         self.e_1 = e_1
         self.e_2 = e_2
         self.e_3 = e_3
         self.inf = inf
-        """
 
     def vector(self, x, y, z):
         """
diff --git a/test/test_utils.py b/test/test_utils.py
index 3571b580..0ab99ecc 100644
--- a/test/test_utils.py
+++ b/test/test_utils.py
@@ -1,8 +1,9 @@
 import unittest
 
-from sympy import S, simplify
+from sympy import expand, S, simplify
 from galgebra.ga import Ga
 from galgebra.mv import Mv
+from galgebra.metric import Simp
 
 
 def com(A, B):
@@ -24,19 +25,29 @@ def assertEqual(self, first, second):
         if isinstance(second, Mv):
             second = second.obj
 
+        # We need to help sympy a little...
+        first = Simp.apply(expand(first))
+        second = Simp.apply(expand(second))
+
+        # Check
         diff = simplify(first - second)
 
         self.assertTrue(diff == 0, "\n%s\n==\n%s\n%s" % (first, second, diff))
 
-    def assertProjEqual(self, X, Y):
+    def assertProjEqual(self, first, second):
         """
         Compare two points, two planes or two lines up to a scalar.
         """
-        assert isinstance(X, Mv)
-        assert isinstance(Y, Mv)
+        assert isinstance(first, Mv)
+        assert isinstance(second, Mv)
+
+        # TODO: this should use Mv methods and not the derived test case methods...
+        first /= self.norm(first)
+        second /= self.norm(second)
 
-        X /= self.norm(X)
-        Y /= self.norm(Y)
+        # We need to help sympy a little...
+        X = Simp.apply(expand(first.obj))
+        Y = Simp.apply(expand(second.obj))
 
         # We can't easily retrieve the sign, so we test both
         diff = simplify(X.obj - Y.obj)
@@ -55,6 +66,11 @@ def assertNotEqual(self, first, second):
         if isinstance(second, Mv):
             second = second.obj
 
+        # We need to help sympy a little...
+        first = Simp.apply(expand(first))
+        second = Simp.apply(expand(second))
+
+        # Check
         diff = simplify(first - second)
 
         self.assertTrue(diff != 0, "\n%s\n!=\n%s\n%s" % (first, second, diff))