Removed duplicate function in unit tests.

tests/test_rules_numerics.py

@@ -8,12 +8,6 @@ from tests.test_rules_poly import tree
 
 class TestRulesNumerics(RulesTestCase):
 
-    def test_add_numerics(self):
-        l0, a, l1 = tree('1,a,2')
-
-        self.assertEqual(add_numerics(l0 + l1, (l0, l1, 1, 2)), 3)
-        self.assertEqual(add_numerics(l0 + a + l1, (l0, l1, 1, 2)), L(3) + a)
-
     def test_add_numerics(self):
         l0, a, l1 = tree('1,a,2')