Fixed negation in rule message.

src/rules/negation.py

@@ -116,7 +116,7 @@ def match_negated_division(node):
     if a.negated and b.negated:
         return [P(node, double_negated_division, ())]
     elif b.negated:
-        return [P(node, single_negated_division, (a, b))]
+        return [P(node, single_negated_division, (a, +b))]
 
     return []
 
@@ -129,7 +129,7 @@ def single_negated_division(root, args):
 
     # FIXME: "-a/b" results in "-(a/b)", which will cause a loop.
 
-    return -a / +b
+    return -a / b
 
 
 MESSAGES[single_negated_division] = \

tests/test_rules_negation.py

@@ -61,7 +61,7 @@ class TestRulesNegation(RulesTestCase):
         l1, l2 = root = tree('1 / -2')
         possibilities = match_negated_division(root)
         self.assertEqualPos(possibilities,
-                [P(root, single_negated_division, (l1, l2))])
+                [P(root, single_negated_division, (l1, +l2))])
 
     def test_match_negated_division_double(self):
         root = tree('-1 / -2')
@@ -72,7 +72,7 @@ class TestRulesNegation(RulesTestCase):
 
     def test_single_negated_division(self):
         l1, l2 = root = tree('1 / -2')
-        self.assertEqualNodes(single_negated_division(root, (l1, l2)),
+        self.assertEqualNodes(single_negated_division(root, (l1, +l2)),
                               -l1 / +l2)
 
     def test_double_negated_division(self):