From e1cd8b47d6fae136124780167bbddd4ac8f1e2c1 Mon Sep 17 00:00:00 2001
From: Francis Russell <francis@unchartedbackwaters.co.uk>
Date: Sun, 14 Apr 2013 11:47:06 +0100
Subject: [PATCH] Avoid introducing a sum when negating a product.

---
 LTA/Symbolic.hs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/LTA/Symbolic.hs b/LTA/Symbolic.hs
index d05f5f6..b52cfc7 100644
--- a/LTA/Symbolic.hs
+++ b/LTA/Symbolic.hs
@@ -187,6 +187,7 @@ instance Num Expr where
   (*) a b = simplify . Product $ empty `addPair` (a, 1) `addPair` (b, 1)
   abs = UnaryFunction Abs
   fromInteger = Literal . fromInteger
+  negate (Product pairSeq) = Product $ transformOverall pairSeq (* (-1))
   negate a = simplify . Sum $ empty `addPair` (a, -1)
   signum = UnaryFunction Signum
 
-- 
2.47.3