diff --git a/Algebra.hs b/Algebra.hs
--- a/Algebra.hs
+++ b/Algebra.hs
@@ -3,7 +3,7 @@
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE TypeFamilies #-}
 
-module Algebra (Semigroup (..), Monoid (mempty), Group (..),
+module Algebra (Semigroup (..), Monoid (mempty), Group (..), Abelian, Idempotent,
                 (+), (-), (*), (/)) where
 
 import Control.Category
diff --git a/alg.cabal b/alg.cabal
--- a/alg.cabal
+++ b/alg.cabal
@@ -1,5 +1,5 @@
 name:                alg
-version:             0.1.1.0
+version:             0.1.1.1
 synopsis:            Algebraic structures
 -- description:         
 license:             BSD3