diff --git a/egison.cabal b/egison.cabal
--- a/egison.cabal
+++ b/egison.cabal
@@ -1,5 +1,5 @@
 Name:                egison
-Version:             2.1.3
+Version:             2.1.4
 Synopsis:            An Interpreter for the Programming Language Egison
 Description:         An interpreter for the programming language Egison.
                      A feature of Egison is the strong pattern match facility.
diff --git a/hs-src/Compiler/egisonc.hs b/hs-src/Compiler/egisonc.hs
--- a/hs-src/Compiler/egisonc.hs
+++ b/hs-src/Compiler/egisonc.hs
@@ -48,15 +48,15 @@
 
 options :: [OptDescr (Options -> IO Options)]
 options = [
-  Option ['V'] ["version"] (NoArg showVersion) "show version number",
+  Option ['V'] ["version"] (NoArg showVersionNumber) "show version number",
   Option ['h', '?'] ["help"] (NoArg showHelp) "show usage information",
   Option ['o'] ["output"] (ReqArg writeExec "FILE") "output file to write"
   ]
 
 -- |Print version information
-showVersion :: Options -> IO Options
-showVersion _ = do
-  putStrLn Language.Egison.Core.egisonVersion
+showVersionNumber :: Options -> IO Options
+showVersionNumber _ = do
+  putStrLn $ showVersion version
   exitWith ExitSuccess
 
 showHelp :: Options -> IO Options
diff --git a/hs-src/Language/Egison/Core.hs b/hs-src/Language/Egison/Core.hs
--- a/hs-src/Language/Egison/Core.hs
+++ b/hs-src/Language/Egison/Core.hs
@@ -13,14 +13,10 @@
 import Data.IORef
 import Paths_egison
 
--- |egison version number
-egisonVersion :: String
-egisonVersion = "2.1.3"
-
 -- |A utility function to display the egison console banner
 showBanner :: IO ()
 showBanner = do
-  putStrLn $ "Egison Version " ++ egisonVersion ++ " (c) 2011-2012 Satoshi Egi"
+  putStrLn $ "Egison Version " ++ showVersion version ++ " (c) 2011-2012 Satoshi Egi"
   putStrLn $ "http://hagi.is.s.u-tokyo.ac.jp/~egi/egison/"
   putStrLn $ "Welcome to Egison Interpreter!"
 
@@ -753,8 +749,7 @@
 constants = [("pi", Float 3.14)
              ]
          
-{- I/O primitives
-Primitive functions that execute within the IO monad -}
+{- I/O primitives -}
 ioPrimitives :: [(String, [EgisonVal] -> IOThrowsError EgisonVal)]
 ioPrimitives = [("open-input-file", makePort ReadMode),
                 ("open-output-file", makePort WriteMode),
diff --git a/hs-src/Language/Egison/Parser.hs b/hs-src/Language/Egison/Parser.hs
--- a/hs-src/Language/Egison/Parser.hs
+++ b/hs-src/Language/Egison/Parser.hs
@@ -114,7 +114,6 @@
      1 -> return $ NumberExpr $ fromInteger $ (*) (-1) $ fst $ Numeric.readHex num !! 0
      _ -> pzero
 
--- |Parser for Integer, base 10
 parseDecimalNumber :: Parser EgisonExpr
 parseDecimalNumber = do
   _ <- try (many (string "#d"))
@@ -124,18 +123,12 @@
      then pzero
      else return $ (NumberExpr . read) $ sign ++ num
 
--- |Parser for a base 10 Integer that will also
---  check to see if the number is followed by
---  an exponent (scientific notation). If so,
---  the integer is converted to a float of the
---  given magnitude.
 parseDecimalNumberMaybeExponent :: Parser EgisonExpr
 parseDecimalNumberMaybeExponent = do
   num <- parseDecimalNumber
   result <- parseNumberExponent num
   return result
 
--- |Parse an integer in any base
 parseNumber :: Parser EgisonExpr
 parseNumber = parseDecimalNumberMaybeExponent <|>
               parseHexNumber <|>
diff --git a/hs-src/Language/Egison/Primitives.hs b/hs-src/Language/Egison/Primitives.hs
--- a/hs-src/Language/Egison/Primitives.hs
+++ b/hs-src/Language/Egison/Primitives.hs
@@ -14,7 +14,6 @@
 
 ---------------------------------------------------
 -- I/O Primitives
--- These primitives all execute within the IO monad
 ---------------------------------------------------
 makePort :: IOMode -> [EgisonVal] -> IOThrowsError EgisonVal
 makePort mode [(World actions), (String filename)] = do