diff --git a/Data/Tensor/TypeLevel.hs b/Data/Tensor/TypeLevel.hs
--- a/Data/Tensor/TypeLevel.hs
+++ b/Data/Tensor/TypeLevel.hs
@@ -25,12 +25,11 @@
 
 import qualified Algebra.Additive as Additive
 import qualified Algebra.Ring as Ring
-import           Control.Monad.Failure
 import           System.IO.Unsafe
 import           Text.Read
 import qualified Text.ParserCombinators.ReadP as P
 
-import           Control.Applicative (Applicative(..), (<$>))
+import           Control.Applicative
 import           Control.Monad hiding
     (mapM_, sequence_, forM_, msum, mapM, sequence, forM)
 import           Data.Foldable
@@ -42,7 +41,7 @@
      (=<<), foldl, foldl1, foldr, foldr1, and, or, any, all, sum, product,
      concat, concatMap, maximum, minimum, elem, notElem)
 import qualified Prelude as P98
-
+import qualified Test.QuickCheck.Arbitrary as QC
 
 infixl 9 !
 -- | a component operator.
@@ -117,17 +116,19 @@
 
 -- | An object that allows component-wise access.
 class (Traversable v) => Vector v where
-  -- | Get a component within f, a context which allows 'Failure'.
-  componentF :: (Failure StringException f) =>
+  -- | Get a component within f, a context which allows failure.
+  componentF :: (Alternative f) =>
                 Axis v -- ^the axis of the component you want
                 -> v a -- ^the target vector
-                -> f a -- ^the component, obtained within a 'Failure' monad
+                -> f a -- ^the component, obtained within a failure
 
   -- | Get a component. This computation may result in a runtime error,
   -- though, as long as the 'Axis' is generated from library functions
   -- such as 'compose', there will be no error.
   component :: Axis v -> v a -> a
-  component axis vec = unsafePerformFailure $ componentF axis vec
+  component axis vec = case componentF axis vec of
+    Just x  -> x
+    Nothing -> error $ "axis out of bound: " ++ show axis
   -- | The dimension of the vector.
   dimension :: v a -> Int
   -- | Create a 'Vector' from a function that maps
@@ -136,13 +137,13 @@
 
 instance Vector Vec where
   componentF axis Vec
-    = failureString $ "axis out of bound: " ++ show axis
+    = empty
   dimension _ = 0
   compose _ = Vec
 
 instance (Vector v) => Vector ((:~) v) where
   componentF (Axis i) vx@(v :~ x)
-    | i==dimension vx - 1 = return x
+    | i==dimension vx - 1 = pure x
     | True                = componentF (Axis i) v
   dimension (v :~ _) = 1 + dimension v
   compose f = let
@@ -172,14 +173,15 @@
 -- thus providing unit vectors.
 class  (Vector v, Ring.C a) => VectorRing v a where
   -- | A vector where 'Axis'th component is unity but others are zero.
-  unitVectorF :: (Failure StringException f) => Axis v -> f (v a)
+  unitVectorF :: (Alternative f) => Axis v -> f (v a)
   -- | pure but unsafe version means of obtaining a 'unitVector'
   unitVector :: Axis v -> v a
-  unitVector = unsafePerformFailure . unitVectorF
+  unitVector axis = case unitVectorF axis of
+    Just x  -> x
+    Nothing -> error $ "axis out of bound: " ++ show axis
 
 instance (Ring.C a) => VectorRing Vec a where
-  unitVectorF axis
-      = failureString $ "axis out of bound: " ++ show axis
+  unitVectorF axis = empty
 
 instance (Ring.C a, VectorRing v a, Additive.C (v a))
     => VectorRing ((:~) v) a where
@@ -188,10 +190,10 @@
       z = Additive.zero
       d = dimension z
       ret
-        | i < 0 || i >= d   = failureString $ "axis out of bound: " ++ show axis
-        | i == d-1          = return $ Additive.zero :~ Ring.one
-        | 0 <= i && i < d-1 = liftM (:~ Additive.zero) $ unitVectorF (Axis i)
-        | True              = return z
+        | i < 0 || i >= d   = empty
+        | i == d-1          = pure $ Additive.zero :~ Ring.one
+        | 0 <= i && i < d-1 = fmap (:~ Additive.zero) $ unitVectorF (Axis i)
+        | True              = pure z
         -- this last guard never matches, but needed to infer the type of z.
 
 instance (Vector v, P98.Num a) => P98.Num ((:~) v a) where
@@ -239,8 +241,3 @@
 vec9 x0 x1 x2 x3 x4 x5 x6 x7 x8 = Vec :~ x0 :~ x1 :~ x2 :~ x3 :~ x4 :~ x5 :~ x6 :~ x7 :~ x8
 vec10 :: a -> a -> a -> a -> a -> a -> a -> a -> a -> a -> Vec10 a
 vec10 x0 x1 x2 x3 x4 x5 x6 x7 x8 x9 = Vec :~ x0 :~ x1 :~ x2 :~ x3 :~ x4 :~ x5 :~ x6 :~ x7 :~ x8 :~ x9
-
-
--- | convert Failure to runtime error
-unsafePerformFailure :: IO a -> a
-unsafePerformFailure = unsafePerformIO
diff --git a/typelevel-tensor.cabal b/typelevel-tensor.cabal
--- a/typelevel-tensor.cabal
+++ b/typelevel-tensor.cabal
@@ -16,7 +16,7 @@
 -- The package version. See the Haskell package versioning policy
 -- (http://www.haskell.org/haskellwiki/Package_versioning_policy) for
 -- standards guiding when and how versions should be incremented.
-Version:             0.1.1
+Version:             0.2
 
 -- A short (one-line) description of the package.
 Synopsis:            Tensors whose ranks and dimensions type-inferred and type-checked.
@@ -68,9 +68,8 @@
   
   -- Packages needed in order to build this package.
   Build-depends: base            == 4.*,
-                 control-monad-failure >= 0.7.0,
-                 numeric-prelude >= 0.3
-
+                 numeric-prelude >= 0.3,
+                 QuickCheck >= 2 
   -- Modules not exported by this package.
   -- Other-modules:       
   
@@ -91,7 +90,6 @@
     type: exitcode-stdio-1.0
     Build-depends: array >= 0.4,
                    base            == 4.*                   ,
-                   control-monad-failure >= 0.7.0  ,
                    numeric-prelude >= 0.3       ,
                    test-framework                           ,
                    test-framework-quickcheck2               ,