From dc1a33f1117c07ede975da2405bca67e79cc2b63 Mon Sep 17 00:00:00 2001
From: Rob Rix <rob.rix@me.com>
Date: Wed, 2 May 2018 18:12:02 -0400
Subject: [PATCH] Derive a Lower instance for Cache.

---
 src/Data/Abstract/Cache.hs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/Data/Abstract/Cache.hs b/src/Data/Abstract/Cache.hs
index b983f9ec0..b870f4fee 100644
--- a/src/Data/Abstract/Cache.hs
+++ b/src/Data/Abstract/Cache.hs
@@ -5,10 +5,12 @@ import Data.Abstract.Address
 import Data.Abstract.Configuration
 import Data.Abstract.Heap
 import Data.Map.Monoidal as Monoidal
+import Data.Semilattice.Lower
 import Prologue
 
 -- | A map of 'Configuration's to 'Set's of resulting values & 'Heap's.
 newtype Cache l t v = Cache { unCache :: Monoidal.Map (Configuration l t v) (Set (v, Heap l v)) }
+  deriving (Lower)
 
 type Cacheable location term value = (Ord (Cell location value), Ord location, Ord term, Ord value)