diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -12,3 +12,7 @@
 
 * Third version. Changed the Languages.UniquenessPeriods.Vector.Data module so that the uniqueness-periods-vector-general package can be fixed and rewritten to 
 follow the requirements. These changes break the previous behaviour, so check the code.
+
+## 0.4.0.0 -- 2020-09-28
+
+* Fourth version. Simplified the uniquenessVariants2GNP function so that it does not use backpermute function from Data.Vector and permutations from Data.List simultanously. 
diff --git a/Languages/UniquenessPeriods/Vector/StrictV.hs b/Languages/UniquenessPeriods/Vector/StrictV.hs
--- a/Languages/UniquenessPeriods/Vector/StrictV.hs
+++ b/Languages/UniquenessPeriods/Vector/StrictV.hs
@@ -5,11 +5,11 @@
 -- Stability   :  Experimental
 -- Maintainer  :  olexandr543@yahoo.com
 --
--- Generalization of the DobutokO.Poetry.StrictV module functionality from 
--- the @dobutokO-poetry-general@ package. 
--- Can be used to get possible permutations of no more than 7 sublists 
--- in the list separated with the elements of the \"whitespace symbols\" 
--- list. 
+-- Generalization of the DobutokO.Poetry.StrictV module functionality from
+-- the @dobutokO-poetry-general@ package.
+-- Can be used to get possible permutations of no more than 7 sublists
+-- in the list separated with the elements of the \"whitespace symbols\"
+-- list.
 
 {-# LANGUAGE CPP, BangPatterns #-}
 
@@ -22,53 +22,63 @@
 import Prelude hiding ((<>))
 #endif
 #endif
-
+#ifdef __GLASGOW_HASKELL__
+#if __GLASGOW_HASKELL__>=710
+/* code that applies only to GHC 7.10.* and higher versions */
+import GHC.Base (mconcat)
+#endif
+#endif
 import qualified Data.Vector as V
-import qualified Data.List as L (permutations,intersperse)
+import qualified Data.List as L (permutations)
+#ifdef __GLASGOW_HASKELL__
+#if __GLASGOW_HASKELL__==708
+/* code that applies only to GHC 7.8.* */
+mconcat = concat
+#endif
+#endif
 
--- | Given a [a] consisting of no more than 7 sublists interspersed with the elements of the first argument, 
--- it returns a 'V.Vector' of possible combinations without repeating of the sublists in different order and for each of them appends also 
--- the information about generalized \"uniqueness periods\" (see @uniqueness-periods-vector@ package) to it and finds out 
--- some different metrics -- named \"properties\". 
--- 
--- Afterwards, depending on these norms some (usually phonetic for the words) properties of the sublists can be specified that 
--- allow to use them for special cases of repetitions (usually, for the words -- poetically or to create a varied melody with them). 
-uniquenessVariants2GN :: 
-  (Eq a, Ord b) => [a] 
-  -> V.Vector ([b] -> b) 
-  -> ([a] -> V.Vector c) 
+-- | Given a [a] consisting of no more than 7 sublists interspersed with the elements of the first argument,
+-- it returns a 'V.Vector' of possible combinations without repeating of the sublists in different order and for each of them appends also
+-- the information about generalized \"uniqueness periods\" (see @uniqueness-periods-vector@ package) to it and finds out
+-- some different metrics -- named \"properties\".
+--
+-- Afterwards, depending on these norms some (usually phonetic for the words) properties of the sublists can be specified that
+-- allow to use them for special cases of repetitions (usually, for the words -- poetically or to create a varied melody with them).
+uniquenessVariants2GN ::
+  (Eq a, Ord b) => [a]
+  -> V.Vector ([b] -> b)
+  -> ([a] -> V.Vector c)
   -> (V.Vector c -> [b])
-  -> [a] 
+  -> [a]
   -> V.Vector ([b],V.Vector b, [a])
-uniquenessVariants2GN whspss vN g1 g2 !xs = uniquenessVariants2GNP [] [] whspss vN g1 g2 xs 
+uniquenessVariants2GN whspss vN g1 g2 !xs = uniquenessVariants2GNP [] [] whspss vN g1 g2 xs
 {-# INLINE uniquenessVariants2GN #-}
-        
--- | Generalized variant of 'uniquenessVariants2GN' with prepending and appending @[a]@ (given as the first and the second argument). 
-uniquenessVariants2GNP :: 
-  (Eq a, Ord b) => [a] 
-  -> [a] 
-  -> [a] 
-  -> V.Vector ([b] -> b) 
-  -> ([a] -> V.Vector c) 
-  -> (V.Vector c -> [b]) 
-  -> [a] 
+
+-- | Generalized variant of 'uniquenessVariants2GN' with prepending and appending @[a]@ (given as the first and the second argument).
+uniquenessVariants2GNP ::
+  (Eq a, Ord b) => [a]
+  -> [a]
+  -> [a]
+  -> V.Vector ([b] -> b)
+  -> ([a] -> V.Vector c)
+  -> (V.Vector c -> [b])
+  -> [a]
   -> V.Vector ([b],V.Vector b, [a])
-uniquenessVariants2GNP !ts !us whspss vN g1 g2 !xs 
+uniquenessVariants2GNP !ts !us whspss vN g1 g2 !xs
   | null . sublistsG whspss $ xs = V.empty
-  | not . null $ whspss = let !v0 = V.fromList . take 8 . sublistsG whspss $ xs in
-     V.fromList . map ((\vs -> let !rs = g2 . g1 $ vs in (rs, (V.map (\f -> f rs) vN), vs)) . concat . L.intersperse (take 1 whspss) . preAppend ts [us] . V.toList . 
-       V.backpermute v0 . V.fromList) . L.permutations $ ([0..(V.length v0 - 1)]::[Int])
+  | not . null $ whspss = let !hd = head whspss in let !ns = take 8 . sublistsG whspss $ xs in
+     V.fromList . map ((\vs -> let !rs = g2 . g1 $ vs in (rs, (V.map (\f -> f rs) vN), vs)) . mconcat . preAppend ts [us]) . L.permutations . map (hd:) $ ns
   | otherwise = error "Languages.UniquenessPeriods.Vector.StrictV.uniquenessVariants2GNP: undefined for the empty third argument. "
 
 -- | Inspired by: https://hackage.haskell.org/package/base-4.14.0.0/docs/src/Data.OldList.html#words
 sublistsG :: Eq a => [a] -> [a] -> [[a]]
-sublistsG whspss xs = 
+sublistsG whspss xs =
  case dropWhile (`elem` whspss) xs of
    [] -> []
    s' -> w : sublistsG whspss s''
      where (w, s'') = break (`elem` whspss) s'
 
--- | Prepends and appends the given two first arguments to the third one. 
+-- | Prepends and appends the given two first arguments to the third one.
 preAppend :: [a] -> [[a]] -> [[a]] -> [[a]]
 #ifdef __GLASGOW_HASKELL__
 #if __GLASGOW_HASKELL__>=804
diff --git a/uniqueness-periods-vector-common.cabal b/uniqueness-periods-vector-common.cabal
--- a/uniqueness-periods-vector-common.cabal
+++ b/uniqueness-periods-vector-common.cabal
@@ -2,7 +2,7 @@
 --   For further documentation, see http://haskell.org/cabal/users-guide/
 
 name:                uniqueness-periods-vector-common
-version:             0.3.0.0
+version:             0.4.0.0
 synopsis:            Generalization of the dobutokO-poetry-general package functionality
 description:         Generalization of the dobutokO-poetry-general package functionality. Can be used to rearrange 7 sublists in the list to obtain somewhat more suitable list for some purposes.
 homepage:            https://hackage.haskell.org/package/uniqueness-periods-vector-common