diff --git a/Numeric/AD/Internal/Tensors.hs b/Numeric/AD/Internal/Tensors.hs
--- a/Numeric/AD/Internal/Tensors.hs
+++ b/Numeric/AD/Internal/Tensors.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE TypeOperators, TemplateHaskell, ScopedTypeVariables #-}
+{-# LANGUAGE TypeOperators, TemplateHaskell, ScopedTypeVariables, FlexibleContexts #-}
 {-# OPTIONS_HADDOCK hide #-}
 -----------------------------------------------------------------------------
 -- |
@@ -27,10 +27,24 @@
 
 infixl 3 :-
 
+-- private, unexported type, so any instances for it will be polymorphic
+
+newtype Showable = Showable (Int -> String -> String)
+
+instance Show Showable where
+  showsPrec d (Showable f) = f d
+
+showable :: Show a => a -> Showable
+showable a = Showable (\d -> showsPrec d a)
+
 -- Polymorphic recursion precludes 'Data' in its current form, as no Data1 class exists
 -- Polymorphic recursion also breaks 'show' for 'Tensors'!
--- factor Show1 out of Lifted?
+
 data Tensors f a = a :- Tensors f (f a)
+
+instance (Functor f, Show (f Showable), Show a) => Show (Tensors f a) where
+  showsPrec d (a :- as) = showParen (d > 3) $ 
+    showsPrec 4 a . showString " :- " . showsPrec 3 (fmap showable <$> as)
 
 instance Functor f => Functor (Tensors f) where
     fmap f (a :- as) = f a :- fmap (fmap f) as
diff --git a/ad.cabal b/ad.cabal
--- a/ad.cabal
+++ b/ad.cabal
@@ -1,5 +1,5 @@
 name:         ad
-version:      1.0.3
+version:      1.0.4
 license:      BSD3
 license-File: LICENSE
 copyright:    (c) Edward Kmett 2010-2011,
@@ -93,15 +93,11 @@
   type: git
   location: git://github.com/ekmett/ad.git
 
-
-
-
 flag TemplateHaskell24
   manual: False
   default: False
 
 library 
-  
   if flag(TemplateHaskell24)
     build-depends: template-haskell >= 2.4 && < 2.5
     extensions: CPP
@@ -114,8 +110,8 @@
     data-reify >= 0.6 && < 0.7, 
     containers >= 0.2 && < 0.5,
     array >= 0.2 && < 0.4,
-    comonad >= 1.0 && < 1.1,
-    streams >= 0.6 && < 0.7
+    comonad >= 1.0.3 && < 1.1,
+    streams >= 0.6.2 && < 0.7
   
   exposed-modules:
     Numeric.AD