diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,3 +1,10 @@
+2009.8.16
+---------
+
+### Feature
+
+* redefine -
+
 2009.7.15
 ---------
 
diff --git a/mps.cabal b/mps.cabal
--- a/mps.cabal
+++ b/mps.cabal
@@ -1,8 +1,8 @@
 Name:                 mps
-Version:              2009.7.4
+Version:              2009.8.16
 Build-type:           Simple
-Synopsis:             OO duck syntax
-Description:          message passing style helpers
+Synopsis:             simply oo
+Description:          DSL that allows one to write Haskell from left to right
 License:              BSD3
 Author:               Wang, Jinjing
 Maintainer:           Wang, Jinjing <nfjinjing@gmail.com>
diff --git a/readme.md b/readme.md
--- a/readme.md
+++ b/readme.md
@@ -9,6 +9,10 @@
     euler_1 = ( [3,6..999] ++ [5,10..999] ).unique.sum
 
 Cheatsheet by [Henry Laxen](http://mazatlan.ning.com/profile/henrylaxen)
--------------------------
+------------------------------------------------------------------------
 
-[lhs source](master/src/Test/MPSexamples.lhs)
+* [html](http://www.maztravel.com/haskell/MPSexamples.html)
+* [pdf](http://www.maztravel.com/haskell/MPSexamples.pdf)
+* [lhs](http://www.maztravel.com/haskell/MPSexamples.lhs)
+
+mirrored [lhs source](master/src/Test/MPSexamples.lhs) in repo.
diff --git a/src/MPS/Light.hs b/src/MPS/Light.hs
--- a/src/MPS/Light.hs
+++ b/src/MPS/Light.hs
@@ -6,7 +6,8 @@
 import Data.Foldable (elem, foldl, foldl', toList, Foldable)
 import Data.Function (on)
 import Debug.Trace
-import Prelude hiding ((.), (^), (>), (/), elem, foldl, foldl1)
+import Prelude hiding ((.), (^), (>), (/), (-), elem, foldl, foldl1)
+import qualified Prelude as Prelude
 import System.FilePath ((</>))
 import qualified Data.Array as A
 import qualified Data.List as L
@@ -14,6 +15,7 @@
 import qualified Data.Set as S
 
 -- base DSL
+{-# INLINE (.) #-}
 (.) :: a -> (a -> b) -> b
 a . f = f a
 infixl 9 .
@@ -30,6 +32,16 @@
 (/) = (</>)
 infixl 5 /
 
+{-# INLINE (-) #-}
+(-) :: (a -> b) -> a -> b
+f - x =  f x
+infixr 0 -
+
+(<->) :: (Num a) => a -> a -> a
+(<->) = (Prelude.-)
+infix 6 <->
+
+
 -- List
 join :: [a] -> [[a]] -> [a]
 join = L.intercalate
@@ -68,7 +80,7 @@
 upto = flip enumFromTo
 
 downto :: (Num t, Enum t) => t -> t -> [t]
-downto m n = [n, n-1.. m]
+downto m n = [n, n <-> 1.. m]
 
 remove_at :: Int -> [a] -> [a]
 remove_at n xs = xs.take n ++ xs.drop (n+1)
@@ -170,7 +182,7 @@
 powerslice :: [a] -> [[a]]
 powerslice xs = [ xs.slice j (j+i) |
   i <- l.downto 1,
-  j <- [0..l - i]
+  j <- [0..l <-> i]
   ]
   where l = xs.length
 
@@ -218,7 +230,7 @@
 
 -- Array
 to_a :: [a] -> A.Array Int a
-to_a xs      = A.listArray (0, xs.length - 1) xs
+to_a xs      = A.listArray (0, xs.length <-> 1) xs
 
 to_a' :: (A.Ix i) => (i, i) -> [e] -> A.Array i e
 to_a' i xs = A.listArray i xs