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diff --git a/MonMap.hs b/MonMap.hs
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+module MonMap where
+
+import qualified Data.Map.Strict as Map
+
+
+newtype MonMap k v = MonMap (Map.Map k v)
+  deriving (Show)
+
+instance Functor (MonMap k) where
+    fmap f (MonMap m) = MonMap (fmap f m)
+
+instance (Ord k, Semigroup v) => Semigroup (MonMap k v) where
+    MonMap m1 <> MonMap m2 = MonMap (Map.unionWith (<>) m1 m2)
+
+instance (Ord k, Monoid v) => Monoid (MonMap k v) where
+    mempty = MonMap mempty
+
+singleton :: k -> v -> MonMap k v
+singleton = (MonMap .) . Map.singleton
+
+lookup :: Ord k => k -> MonMap k v -> Maybe v
+lookup k (MonMap m) = Map.lookup k m