diff --git a/ChangeLog b/ChangeLog
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2010-06-21  John D. Ramsdell  <ramsdell@mitre.org>
+
+	* agum.cabal (Version): Released as version 2.3.
+
+	* agum.cabal (Build-Depends): changes dependency to
+	base >= 3 && <5, containers
+
 2009-09-17  John D. Ramsdell  <ramsdell@mitre.org>
 
 	* agum.cabal (Version): Released as version 2.2.
diff --git a/agum.cabal b/agum.cabal
--- a/agum.cabal
+++ b/agum.cabal
@@ -1,5 +1,5 @@
 Name:			agum
-Version:		2.2
+Version:		2.3
 Maintainer:		ramsdell@mitre.org
 Cabal-Version:		>= 1.2
 License:		GPL
@@ -19,7 +19,7 @@
 Extra-Source-Files:	readme.txt ChangeLog Makefile
 
 Library
-  Build-Depends:	base <= 4.1.0.0, containers
+  Build-Depends:	base >= 3 && < 5, containers
   Exposed-Modules:	Algebra.AbelianGroup.UnificationMatching
                         Algebra.AbelianGroup.IntLinEq
   Hs-Source-Dirs:	src
@@ -28,7 +28,7 @@
 
 Executable agum
   Main-Is:		Algebra/AbelianGroup/Main.hs
-  Build-Depends:	base <= 4.1.0.0, containers
+  Build-Depends:	base >= 3 && < 5, containers
   Other-Modules:	Algebra.AbelianGroup.UnificationMatching
                         Algebra.AbelianGroup.IntLinEq
   Hs-Source-Dirs:	src
diff --git a/src/Algebra/AbelianGroup/UnificationMatching.hs b/src/Algebra/AbelianGroup/UnificationMatching.hs
--- a/src/Algebra/AbelianGroup/UnificationMatching.hs
+++ b/src/Algebra/AbelianGroup/UnificationMatching.hs
@@ -40,7 +40,7 @@
 --
 -- [Associativity] (x + y) + z = x + (y + z)
 --
--- [Group Identity] x + 0 = x
+-- [Identity Element] x + 0 = x
 --
 -- [Cancellation] x + -x = 0
 --
@@ -93,7 +93,7 @@
 --
 -- * x + y = y + x                 Commutativity
 -- * (x + y) + z = x + (y + z)     Associativity
--- * x + 0 = x                     Group identity
+-- * x + 0 = x                     Identity Element
 -- * x + -x = 0                    Cancellation
 
 -- A substitution maps variables to terms.  A substitution s is
@@ -110,18 +110,18 @@
 -- Substitition s is more general than s' if there is a substitition
 -- s" such that s' = s" o s.
 
--- A term is represented by the group identity, or as the sum of
+-- A term is represented by the identity element, or as the sum of
 -- factors.  A factor is the product of a non-zero integer coefficient
 -- and a variable.  In this representation, no variable occurs twice.
 -- Thus a term is represented by a finite map from variables to
 -- non-zero integers.
 
--- | A term in an Abelian group is represented by the group identity
+-- | A term in an Abelian group is represented by the identity
 -- element, or as the sum of factors.  A factor is the product of a
 -- non-zero integer coefficient and a variable.  No variable occurs
--- twice in a term.  For the show and read methods, zero is the group
--- identity, the plus sign is the group operation, and the minus sign
--- is the group inverse.
+-- twice in a term.  For the show and read methods, zero is the
+-- identity element, the plus sign is the group operation, and the
+-- minus sign is the group inverse.
 newtype Term = Term (Map String Int) deriving Eq
 
 -- Constructors