diff --git a/CPSPrint.hs b/CPSPrint.hs
--- a/CPSPrint.hs
+++ b/CPSPrint.hs
@@ -8,7 +8,7 @@
 import Data.Char
 import Control.Arrow ((***))
 import Data.Map (unions, singleton)
-import Data.Monoid
+import Data.Monoid hiding ((<>))
 
 import CPSScheme
 import Common
diff --git a/Common.hs b/Common.hs
new file mode 100644
--- /dev/null
+++ b/Common.hs
@@ -0,0 +1,37 @@
+{-|
+  Some convenience definitions.
+ -}
+{-# LANGUAGE TypeOperators #-}
+module Common where
+
+import qualified Data.Map as M
+import qualified Data.Set as S
+import Control.Monad (liftM)
+
+-- * Type aliases
+
+-- | Convenient alias for a partial map
+type a :⇀ b = M.Map a b
+infixl 8 :⇀
+
+-- | Convenient alias for a product type
+type a :× b = (a,b)
+infixl 9 :×
+
+-- * Partial map functions
+
+-- | A function used to write map updates resembling the mathematical syntax m [ k &#8614; v]  as m `upd` [k &#8614; v]
+upd :: (Ord k) => k :⇀a -> [k :× a] -> k :⇀ a
+upd map list = M.union (M.fromList list) map
+
+-- | A functorial variant of 'upd'
+upd' :: (Ord k, Functor f) => f (k :⇀ a) -> [k :× a] -> f (k :⇀ a)
+upd' map list = fmap (`upd` list) map
+
+-- | For use in the argument list of 'upd'
+(↦) :: k -> v -> k :× v
+k ↦ v = (k,v)
+
+-- | A monadically lifted unions
+unionsM :: (Monad m, Ord k) => [m (k :⇀ a)] -> m (k :⇀ a)
+unionsM = liftM M.unions . sequence
diff --git a/shivers-cfg.cabal b/shivers-cfg.cabal
--- a/shivers-cfg.cabal
+++ b/shivers-cfg.cabal
@@ -1,5 +1,5 @@
 Name:                shivers-cfg
-Version:             0.1
+Version:             0.1.1
 Synopsis:            Implementation of Shivers' Control-Flow Analysis
 Description:
         In his 1991 dissertation, Olin Shivers introduces a concept
@@ -25,4 +25,4 @@
 Library
   Build-depends:       containers, base >=4 && <5, mtl, process, directory,
                        pretty, HPDF, language-dot
-  Exposed-modules:     Eval, CPSScheme, ExCF, AbsCF, CPSPrint, CFGraph
+  Exposed-modules:     Eval, CPSScheme, ExCF, AbsCF, CPSPrint, CFGraph, Common