diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -46,4 +46,9 @@
 
 * Fifth version. Added a new module Phladiprelio.General.Datatype3 with extended functionality for
   PhLADiPreLiO.
- 
+
+ ## 0.5.1.0 -- 2023-11-17
+
+* Fifth version revised A. Fixed two issues that led to incorrect behaviour of readU2 and readU3
+  functions and also fixed issue with splitL0 function.
+
diff --git a/Phladiprelio/General/Datatype.hs b/Phladiprelio/General/Datatype.hs
--- a/Phladiprelio/General/Datatype.hs
+++ b/Phladiprelio/General/Datatype.hs
@@ -135,13 +135,13 @@
 
 -- | Is a way to read duration of the additional added time period into the line.
 readU2 :: String -> Double
-readU2 xs@(y:ys) = fromMaybe 1.0 (readMaybe (y:'.':ys)::Maybe Double)
+readU2 xs@(y:ys) = fromMaybe 1.0 (readMaybe (y:'.':(if null ys then "0" else ys))::Maybe Double)
 readU2 _ = 1.0
 {-# INLINABLE readU2 #-}
 
 -- | Is a way to read duration of the additional added time period into the line.
 readU3 :: Double -> String -> Double
-readU3 def xs@(y:ys) = fromMaybe def (readMaybe (y:'.':ys)::Maybe Double)
+readU3 def xs@(y:ys) = fromMaybe def (readMaybe (y:'.':(if null ys then "0" else ys))::Maybe Double)
 readU3 def _ = def
 {-# INLINABLE readU3 #-}
 
diff --git a/Phladiprelio/General/Datatype3.hs b/Phladiprelio/General/Datatype3.hs
--- a/Phladiprelio/General/Datatype3.hs
+++ b/Phladiprelio/General/Datatype3.hs
@@ -26,7 +26,7 @@
 import Phladiprelio.General.Datatype (readU2)
 
 splitL0 :: String -> [String]
-splitL0 = groupBy (\x y -> (isDigit x && isDigit y) || (isLetter x && isLetter y) || ((x == '=' || x == '_') && isDigit y))
+splitL0 = groupBy (\x y -> (isDigit x && isDigit y) || (x /= '_' && x /= '=' && not (isDigit x) && y /= '_' && y /= '=' && not (isDigit y)) || ((x == '=' || x == '_') && isDigit y))
 {-# INLINE splitL0 #-}
 
 data Read0 = A {-# UNPACK #-} !Double | B {-# UNPACK #-} !Double | C String deriving (Eq, Show)
diff --git a/phladiprelio-general-datatype.cabal b/phladiprelio-general-datatype.cabal
--- a/phladiprelio-general-datatype.cabal
+++ b/phladiprelio-general-datatype.cabal
@@ -1,6 +1,6 @@
 cabal-version:      1.24
 name:               phladiprelio-general-datatype
-version:            0.5.0.0
+version:            0.5.1.0
 synopsis:           Extended functionality of PhLADiPreLiO
 description:        Can be used not only for language, but also for simpler music and lyrics composing.
 homepage:           https://hackage.haskell.org/package/phladiprelio-general-datatype