diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -3,3 +3,7 @@
 ## 0.1.0.0 -- 2020-09-17
 
 * First version. Released on an unsuspecting world.
+
+## 0.1.1.0 -- 2020-09-17
+
+* First version revised A. Defined intervalNRealFrac for the equal two first arguments (though this can be rarely useful). 
diff --git a/Languages/UniquenessPeriods/Vector/Filters.hs b/Languages/UniquenessPeriods/Vector/Filters.hs
--- a/Languages/UniquenessPeriods/Vector/Filters.hs
+++ b/Languages/UniquenessPeriods/Vector/Filters.hs
@@ -29,7 +29,9 @@
   -> Int
   -> b 
   -> Int
-intervalNRealFrac minE maxE n x = zero2One . ceiling $ fromIntegral n * (x - minE) / (maxE - minE)
+intervalNRealFrac minE maxE n x 
+ | maxE == minE = round (0.5 * fromIntegral n)
+ | otherwise = zero2One . ceiling $ fromIntegral n * (x - minE) / (maxE - minE)
 {-# INLINE intervalNRealFrac #-} 
 
 zero2One :: Int -> Int
diff --git a/uniqueness-periods-vector-filters.cabal b/uniqueness-periods-vector-filters.cabal
--- a/uniqueness-periods-vector-filters.cabal
+++ b/uniqueness-periods-vector-filters.cabal
@@ -2,7 +2,7 @@
 --   For further documentation, see http://haskell.org/cabal/users-guide/
 
 name:                uniqueness-periods-vector-filters
-version:             0.1.0.0
+version:             0.1.1.0
 synopsis:            A library allows to change the structure of the 'RealFrac' function output.
 description:         A library allows to change the structure of the 'RealFrac' function output. At the moment only the equal intervals are supported.