diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -42,3 +42,7 @@
 ## 0.4.0.0 -- 2019-12-05
 
 * Fourth version. Fixed issues with the sound conversions. Now they works properly.
+
+## 0.4.0.1 -- 2019-12-06
+
+* Fourth version revised A. Better documentated. Some minor code changes.
diff --git a/Main.hs b/Main.hs
--- a/Main.hs
+++ b/Main.hs
@@ -15,12 +15,12 @@
 ) where
 
 import Data.Maybe (isJust,fromJust)
-import System.IO 
-import System.Environment
+import System.IO
+import System.Environment (getArgs)
 import System.Process
-import EndOfExe
+import EndOfExe (showE)
 import Paths_mmsyn6ukr
-import Melodics.Ukrainian
+import Melodics.Ukrainian (appendS16LEFile, nSymbols, convertToProperUkrainian)
 
 {-
 -- Inspired by: https://mail.haskell.org/pipermail/beginners/2011-October/008649.html
diff --git a/Melodics/Ukrainian.hs b/Melodics/Ukrainian.hs
--- a/Melodics/Ukrainian.hs
+++ b/Melodics/Ukrainian.hs
@@ -35,7 +35,6 @@
   data1 <- B.readFile file
   let dataN = B.drop 44 data1 in return dataN
 
-
 -- | The function that actually produces a .raw file.
 appendS16LEFile ::  V.Vector String -> Handle -> IO ()
 appendS16LEFile xs hdl | not (V.null xs) = 
@@ -64,7 +63,7 @@
                        | otherwise = return ()
 
 -- | The function that converts a written Ukrainian text into the sounding in the program phonetical respesentation. 
--- It is not exact phonetically but you can make for yourself a general imression of the Ukrainian sounding.
+-- It is not exact phonetically but you can make for yourself a general impression of the Ukrainian sounding.
 convertToProperUkrainian :: String -> V.Vector String
 convertToProperUkrainian ys = toVector . correctA . applyChanges . createTuplesByAnalysis . changeJotted . secondConv . wasFstConverted . filterUkr $ ys
 
@@ -125,9 +124,6 @@
                         | otherwise = x:changeJotted (y:z:zs)
 changeJotted xs = xs
 
-isNotVowel :: Char -> Bool
-isNotVowel = getBFst' (True, V.fromList $ zip "\1072\1077\1080\1086\1091\1102\1103\1108\1110\1111" (repeat False))
-
 applyChanges :: [(String, Triple)] -> [(String, Triple)]
 applyChanges (z:t:zs) | snd z == T = 
   getBFst' ((fst z, Z), V.fromList . zip ["\1075","\1076","\1076\1079","\1078","\1079","\1082","\1085\1090",
@@ -306,15 +302,18 @@
           k = length ks
 
 takeFromFT_ :: Int -> [(String, Triple)] -> String
-takeFromFT_ n ts = takeFromFT n (filter (\(xs, y) -> (xs /= "1" && xs /= "0")) ts)
+takeFromFT_ n ts = takeFromFT n (filter (\(xs, _) -> (xs /= "1" && xs /= "0")) ts)
 
 toVector :: [(String, Triple)] -> V.Vector String
-toVector ts = V.fromList . mapI2 (\x -> not . null . fst $ x) fst (\y -> []) $ ts
+toVector ts = V.fromList . mapI2 (\x -> not . null . fst $ x) fst (\_ -> []) $ ts
 
 isUkrainian :: Char -> Bool
 isUkrainian y | (y >= '\1040' && y <= '\1065') || (y >= '\1070' && y <= '\1097') = True
               | otherwise = getBFst' (False, V.fromList . map (\x -> (x, True)) $ "'-\700\1028\1030\1031\1068\1100\1102\1103\1108\1110\1111\1168\1169\8217") y
 
+-- | Function that converts the first command line argument given, which is a digit in the range @[0..9]@, 
+-- to the upper bound of number of symbols that the 'Main.main' function reads from the @stdin@ for sounding.
+-- The default value (no / some other input) is 31416. 
 nSymbols :: String -> Int
 nSymbols xs | null xs = 31416::Int
             | otherwise = getBFst' (31416::Int, V.generate 10 (\n -> (n, (10^n + 1)::Int))) (let temp = read xs::Int in if temp <= 9 && temp >= 1
diff --git a/mmsyn6ukr.cabal b/mmsyn6ukr.cabal
--- a/mmsyn6ukr.cabal
+++ b/mmsyn6ukr.cabal
@@ -2,7 +2,7 @@
 -- documentation, see http://haskell.org/cabal/users-guide/
 
 name:                mmsyn6ukr
-version:             0.4.0.0
+version:             0.4.0.1
 synopsis:            A musical instrument synthesizer or a tool for Ukrainian language listening
 description:         A program can be used as a musical instrument synthesizer or for Ukrainian speech synthesis especially for poets and writers
 homepage:            https://hackage.haskell.org/package/mmsyn6ukr