diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -6,10 +6,12 @@
 
 ## 0.2.0.0 -- 2020-09-07
 
-* Second version. Added the new type constuctor UG3 to the UniquenessGeneral1 data type. Added new functions related to uniquenessPeriodsVector3. 
+* Second version. Added the new type constuctor UG3 to the UniquenessGeneral1 data type. Added new functions related to uniquenessPeriodsVector3.
 
 ## 0.3.0.0 -- 2020-09-09
 
-* Third version. Fixed issue with helpUPV3 function. 
+* Third version. Fixed issue with helpUPV3 function.
 
+## 0.3.1.0 -- 2020-10-14
 
+* Third version revised A. Changed the representation of the helpUPV3 function. Some related code and documentation changes.
diff --git a/String/Languages/UniquenessPeriods/Vector.hs b/String/Languages/UniquenessPeriods/Vector.hs
--- a/String/Languages/UniquenessPeriods/Vector.hs
+++ b/String/Languages/UniquenessPeriods/Vector.hs
@@ -63,15 +63,15 @@
  | V.null v = V.empty
  | otherwise = let !v1 = V.indexed v in let !vs = V.toList . V.findIndices (`elem` whspss) $ v in 
     let f !x = if V.null x then Nothing 
-                else Just . (\vws (v2,v3) -> ((helpUPV3 vws . V.toList . V.map fst $ v2,snd . 
+                else Just . (\vws (v2,v3) -> ((helpUPV3 vws [] . V.toList . V.map fst $ v2,snd . 
                   V.unsafeIndex v2 $ 0),v3)) vs . V.partition (\(_,xs) -> xs == (snd . V.unsafeIndex x $ 0)) $ x in 
                     V.filter (\(ys,!zs) -> not (null ys) && (zs `notElem` whspss)) . V.unfoldr f $ v1
 
 -- | Is used inside the 'uniquenessPeriodsVector3'. Both list arguments of non-negative numbers (if not empty) must be sorted in the ascending order.
-helpUPV3 :: [Int] -> [Int] -> [Int]
-helpUPV3 (z:zs) (x:y:xs) 
- | compare ((x - z) * (y - z)) 0 == LT = (y - x):helpUPV3 zs (y:xs)
- | compare y z == GT = helpUPV3 zs (x:y:xs)
- | otherwise = helpUPV3 (z:zs) (y:xs)
-helpUPV3 _ _ = []
+helpUPV3 :: [Int] -> [Int] -> [Int] -> [Int]
+helpUPV3 (z:zs) acc (x:y:xs) 
+ | compare ((x - z) * (y - z)) 0 == LT = helpUPV3 zs ((y - x):acc) (y:xs)
+ | compare y z == GT = helpUPV3 zs acc (x:y:xs)
+ | otherwise = helpUPV3 (z:zs) acc (y:xs)
+helpUPV3 _ acc _ = acc
 
diff --git a/uniqueness-periods-vector.cabal b/uniqueness-periods-vector.cabal
--- a/uniqueness-periods-vector.cabal
+++ b/uniqueness-periods-vector.cabal
@@ -2,7 +2,7 @@
 -- further documentation, see http://haskell.org/cabal/users-guide/
 
 name:                uniqueness-periods-vector
-version:             0.3.0.0
+version:             0.3.1.0
 synopsis:            Generalization of the uniqueness-periods and uniqueness-periods-general packages functionality.
 description:         Generalization of the uniqueness-periods and uniqueness-periods-general packages functionality.
 homepage:            https://hackage.haskell.org/package/uniqueness-periods-vector