Added a unit test.

tests/test_line.py

@@ -135,6 +135,9 @@ class TestLine(unittest.TestCase):
         mul = N('*', a, l2)
         self.assertEquals(generate_line(mul), 'a * 2')
 
+        mul = N('*', l2, N('^', a, l2))
+        self.assertEquals(generate_line(mul), '2 * a ^ 2')
+
     def test_plus_to_minus(self):
         plus = N('+', L(1), -L(2))
         self.assertEquals(generate_line(plus), '1 - 2')