From 383296fc80db17317dd385821265003c01134f50 Mon Sep 17 00:00:00 2001
From: Vivien Maisonneuve <v.maisonneuve@gmail.com>
Date: Thu, 19 Jun 2014 09:15:55 +0200
Subject: [PATCH] Fix Expression.__hash__

---
 pypol/linear.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pypol/linear.py b/pypol/linear.py
index 8f73fd3..2c71c02 100644
--- a/pypol/linear.py
+++ b/pypol/linear.py
@@ -271,7 +271,7 @@ class Expression:
                 self.constant == other.constant
 
     def __hash__(self):
-        return hash((self._coefficients, self._constant))
+        return hash((tuple(sorted(self._coefficients.items())), self._constant))
 
     def _toint(self):
         lcm = functools.reduce(lambda a, b: a*b // gcd(a, b),
-- 
2.20.1