diff --git a/Core.hs b/Core.hs
index 7c04844..86d46f6 100644
--- a/Core.hs
+++ b/Core.hs
@@ -139,7 +139,8 @@ collectV (CrApp e0 e1)=collectV e0 `S.union` collectV e1
 collectV (CrLet _ bs e)=S.unions $ map collectV $ e:map snd bs
 collectV (CrCase e cs)=S.unions $ map collectV $ e:map thr3 cs
 collectV (CrLm as e)=collectV e
-
+collectV (CrByte _)=S.empty
+collectV e=error $ "collectV: "++show e
 
 
 
diff --git a/Main.hs b/Main.hs
index b0897e5..bf1ad44 100644
--- a/Main.hs
+++ b/Main.hs
@@ -51,7 +51,7 @@ data Option=Option
 
 -- | Parse arguments to 'Command'. Note this is a total function.
 parseArgs :: [String] -> Command
-parseArgs []=ShowMessage version
+parseArgs []=ShowMessage $ version++"\n"++help
 parseArgs ("-v":_)=ShowMessage version
 parseArgs ("--version":_)=ShowMessage version
 parseArgs ("-h":_)=ShowMessage $ version++"\n"++help
@@ -102,7 +102,7 @@ execCommand (Compile opt from)=partialChain opt from $
     where f g=runProcessWithIO (putStr . g)
 
 partialChain opt from (c0,c1,g0,g1,s0,s1,b)=do
-    dir<-liftM takeDirectory $ Paths_hs2bf.getDataFileName "Prelude.hs"
+    dir<-Paths_hs2bf.getDataDir
     let (mod,env)=analyzeName from dir
     xs<-Front.collectModules env mod
     let cr  =xs   >>= Front.compile
@@ -142,7 +142,7 @@ help=unlines $
     ,"  -Sgr: to GMachine (simplified)"
     ,"  -Ss : to SAM"
     ,"  -Ssf: to SAM (most simplified)"
-    ,"  -Sr : to SCGR"
+--    ,"  -Sr : to SCGR" -- not implemented
     ,"  -Sb : to BF"
     ,"  --addr n : use n byte for pointer arithmetic"
     ,"  --debug : include detailed error message (this will make the program a LOT larger)"
diff --git a/SCGR.hs b/SCGR.hs
index 6b617d5..5b0a86b 100644
--- a/SCGR.hs
+++ b/SCGR.hs
@@ -1,4 +1,4 @@
--- | Super-cool-graph-representation
+-- | Super-cool-graph-representation (this module is not used now)
 --
 -- There are 3 goals in optimization:
 --
diff --git a/hs2bf.cabal b/hs2bf.cabal
index 4dbc694..debefdd 100644
--- a/hs2bf.cabal
+++ b/hs2bf.cabal
@@ -1,17 +1,19 @@
 name:            hs2bf
 cabal-version:   >=1.2
-version:         0.5
+version:         0.6
 author:          xanxys
 maintainer:      xanxys@gmail.com
 synopsis:        Haskell to Brainfu*k compiler
 license:         BSD3
 license-File:    LICENSE
 category:        Compiler
-description:     Haskell to Brainfu*k compiler.
+description:
+    Proof of concept implementation of Haskell to Brainfu*k compiler.
+    You can find examples of compilable codes at http://www.xanxys.net/public/hs2bf-demo/
 build-type:      Simple
 data-files:      Prelude.hs
 data-dir:        test
-tested-with:     GHC==6.10.4
+tested-with:     GHC==6.10.4,GHC==6.12.1
 extra-source-files:
     Front.hs Core.hs GMachine.hs SAM.hs SCGR.hs Brainfuck.hs
     Util.hs SRuntime.hs
diff --git a/test/Prelude.hs b/test/Prelude.hs
deleted file mode 100644
index b214cf9..0000000
--- a/test/Prelude.hs
+++ /dev/null
@@ -1,174 +0,0 @@
-
--- internal
-seq=undefined
-undefined=undefined
-addByteRaw=undefined
-subByteRaw=undefined
-cmpByteRaw=undefined
-
-
--- generic combinanors
-infixr 9 .
-(.) f g x=f (g x)
-
-infixr 0 $
-f $ x=f x
-
-infixr 0 $!
-f $! x=x `seq` (f x)
-
-
-id x=x
-flip f x y=f y x
-
-
--- boolean
-data Bool
-    =False
-    |True
-
-infixr 2 ||
-x || y=
-    case x of
-        True  -> True
-        False -> y
-
-infixr 3 &&
-x && y=
-    case x of
-        False -> False
-        True  -> y
-
-otherwise=True
-
-
--- maybe
-data Maybe a
-    =Nothing
-    |Just a
-
-
--- either
-data Either a b
-    =Left a
-    |Right b
-
-
--- ordering
-data Ordering
-    =EQ -- 0
-    |LT -- 1
-    |GT -- 2
-
-
--- tuple
-data XT1 a=XT1 a
-data XT2 a b=XT2 a b
-data XT3 a b c=XT3 a b c
-
-
-
--- list
-data XList a
-    =XCons a (XList a)
-    |XNil
-
-
-head (x:xs)=x
-tail (x:xs)=xs
-
-reverse []=[]
-reverse (x:xs)=reverse xs++[x]
-
-map f []=[]
-map f (x:xs)=f x:map f xs
-
-filter f []=[]
-filter f (x:xs)
-    |f x       = x:filter f xs
-    |otherwise = filter f xs
-
-(x:xs) !! n
-    |n `eqByte` 0 = x
-    |otherwise    = xs !! (n `subByte` 1)
-
-xs ++ ys=
-    case xs of
-        []   -> ys
-        x:xs -> x:(xs++ys)
-
-
-{- I don't know why, but this code doesn't work!
-[]++ys=ys
-(x:xs)++ys=x:(xs++ys)
--}
-
-
-
-length []=0
-length (x:xs)=1 `addByte` (length xs)
-
-foldr f z []=z
-foldr f z (x:xs)=f x (foldr f z xs)
-
-foldl f z []=z
-foldl f z (x:xs)=foldl f (f x z) xs
-
-
--- I/O
-data E
-    =Input (Char -> E)
-    |Output !Char E
-    |Halt
-
-
-
-
-
-
-addByte x y=x `seq` (y `seq` (addByteRaw x y))
-subByte x y=x `seq` (y `seq` (subByteRaw x y))
-cmpByte x y=x `seq` (y `seq` (cmpByteRaw x y))
-
-eqByte x y=case cmpByte x y of
-    EQ -> True
-    s  -> False
-
-ltByte x y=case cmpByte x y of
-    LT -> True
-    s  -> False
-
-gtByte x y=case cmpByte x y of
-    GT -> True
-    s  -> False
-
-leByte x y=case cmpByte x y of
-    GT -> False
-    s  -> True
-
-geByte x y=case cmpByte x y of
-    LT -> False
-    s  -> True
-
-{-
-data Int
-    =PInt Byte
-    |NInt Byte
-
-
-negateInt (PInt x)=NInt x
-negateInt (NInt x)=PInt x
-
-addInt (PInt x) (PInt y)=PInt $ x `addByte` y
-addInt (NInt x) (NInt y)=NInt $ x `addByte` y
-addInt (PInt x) (NInt y)
-    |x `gtByte` y = PInt $ x `subByte` y
-    |otherwise    = NInt $ y `subByte` x
-addInt (NInt x) (PInt y)
-    |x `gtByte` y = NInt $ x `subByte` y
-    |otherwise    = PInt $ y `subByte` x
-
--}
-
-
-