diff --git a/Data/Array/Repa/Internals/Elt.hs b/Data/Array/Repa/Internals/Elt.hs
--- a/Data/Array/Repa/Internals/Elt.hs
+++ b/Data/Array/Repa/Internals/Elt.hs
@@ -15,10 +15,14 @@
 -- values. The argument type has kind ?, not just * or #.
 
 -- | Element types that can be stored in Repa arrays.
+--   Repa uses `Data.Vector.Unboxed` to store the actual data. The implementation
+--   of this library is based on type families and picks an efficient, specialised
+--   representation for every element type. In particular, unboxed vectors of pairs
+--   are represented as pairs of unboxed vectors.
 class (Show a, Unbox a)	=> Elt a where
 
 	-- | We use this to prevent bindings from being floated inappropriatey.
-	--   Doing a `seq` sometimes isn't enough, because the GHC simpplifier can 
+	--   Doing a `seq` sometimes isn't enough, because the GHC simplifier can 
 	--   erase these, and/or still move around the bindings.
 	touch :: a -> IO ()
 
@@ -43,20 +47,6 @@
  one  = True
 
 
--- Tuple ----------------------------------------------------------------------
-instance (Elt a, Elt b) => Elt (a, b) where
- {-# INLINE touch #-}
- touch (a, b) 
-  = do	touch a
-	touch b
-	
- {-# INLINE zero #-}
- zero = (zero, zero)
-
- {-# INLINE one #-}
- one =  (one, one)
-
-
 -- Floating -------------------------------------------------------------------
 instance Elt Float where
  {-# INLINE touch #-}
@@ -161,3 +151,81 @@
 
  {-# INLINE one #-}
  one = 1
+
+
+-- Tuple ----------------------------------------------------------------------
+instance (Elt a, Elt b) => Elt (a, b) where
+ {-# INLINE touch #-}
+ touch (a, b) 
+  = do	touch a
+	touch b
+	
+ {-# INLINE zero #-}
+ zero = (zero, zero)
+
+ {-# INLINE one #-}
+ one =  (one, one)
+
+
+instance (Elt a, Elt b, Elt c) => Elt (a, b, c) where
+ {-# INLINE touch #-}
+ touch (a, b, c) 
+  = do	touch a
+	touch b
+	touch c
+	
+ {-# INLINE zero #-}
+ zero = (zero, zero, zero)
+
+ {-# INLINE one #-}
+ one =  (one, one, one)
+
+
+instance (Elt a, Elt b, Elt c, Elt d) => Elt (a, b, c, d) where
+ {-# INLINE touch #-}
+ touch (a, b, c, d) 
+  = do	touch a
+	touch b
+	touch c
+	touch d
+	
+ {-# INLINE zero #-}
+ zero = (zero, zero, zero, zero)
+
+ {-# INLINE one #-}
+ one =  (one, one, one, one)
+
+
+instance (Elt a, Elt b, Elt c, Elt d, Elt e) => Elt (a, b, c, d, e) where
+ {-# INLINE touch #-}
+ touch (a, b, c, d, e) 
+  = do	touch a
+	touch b
+	touch c
+	touch d
+	touch e
+	
+ {-# INLINE zero #-}
+ zero = (zero, zero, zero, zero, zero)
+
+ {-# INLINE one #-}
+ one =  (one, one, one, one, one)
+
+
+instance (Elt a, Elt b, Elt c, Elt d, Elt e, Elt f) => Elt (a, b, c, d, e, f) where
+ {-# INLINE touch #-}
+ touch (a, b, c, d, e, f) 
+  = do	touch a
+	touch b
+	touch c
+	touch d
+	touch e
+	touch f
+	
+ {-# INLINE zero #-}
+ zero = (zero, zero, zero, zero, zero, zero)
+
+ {-# INLINE one #-}
+ one =  (one, one, one, one, one, one)
+
+
diff --git a/repa.cabal b/repa.cabal
--- a/repa.cabal
+++ b/repa.cabal
@@ -1,5 +1,5 @@
 Name:                repa
-Version:             2.0.0.4
+Version:             2.0.1.1
 License:             BSD3
 License-file:        LICENSE
 Author:              The DPH Team
@@ -11,10 +11,10 @@
 Homepage:            http://repa.ouroborus.net
 Bug-reports:         repa@ouroborus.net
 Description:
-        Repa provides high performance, regular, multi-dimensional, shape polymorphic parallel arrays.
-        All numeric data is stored unboxed. Functions written with the Repa combinators
-        are automatically parallel provided you supply +RTS -Nwhatever on the command
-        line when running the program.
+        Repa provides high performance, regular, multi-dimensional, shape polymorphic
+        parallel arrays. All numeric data is stored unboxed. Functions written with
+        the Repa combinators are automatically parallel provided you supply
+        +RTS -Nwhatever on the command line when running the program.
 
 Synopsis:
         High performance, regular, shape polymorphic parallel arrays.