Fix Expression.__rsub__

[linpy.git] / tests / test_linear.py

diff --git a/tests/test_linear.py b/tests/test_linear.py
index 93fc838..4079d75 100644 (file)
--- a/tests/test_linear.py
+++ b/tests/test_linear.py
@@ -99,6 +99,7 @@ class TestExpression(unittest.TestCase):
     def test_sub(self):
         self.assertEqual(self.x - self.x, 0)
         self.assertEqual(self.e - 3, self.x - 2*self.y)
+        self.assertEqual(0 - self.x, -self.x)
 
     def test_mul(self):
         self.assertEqual(self.pi * 7, 22)