diff --git a/aern2-mp.cabal b/aern2-mp.cabal
--- a/aern2-mp.cabal
+++ b/aern2-mp.cabal
@@ -1,5 +1,5 @@
 name:           aern2-mp
-version:        0.1.3.0
+version:        0.1.3.1
 cabal-version:  >= 1.9.2
 build-type:     Simple
 homepage:       https://github.com/michalkonecny/aern2
@@ -11,14 +11,17 @@
 extra-source-files:  changelog.md
 stability:      experimental
 category:       Math
-synopsis:       Multi-precision floats via rounded (MPFR)
+synopsis:       Multi-precision ball (interval) arithmetic
 Description:
-  Arbitrary-precision dyadic numbers and safely-rounded interval arithmetic:
+  This package provides the following types:
   .
   * Dyadic:  variable-precision floats with exact ring operations
   .
-  * MPBall: float ± error bound with field & elementary (interval-like) operations
+  * MPBall: float ± error bound with field & elementary interval-like operations
   .
+  The types have instances of both <https://hackage.haskell.org/package/mixed-types-num MixedTypeNumPrelude> 
+  type classes as well as with traditional Prelude type classes.
+  .
   There is a plan to add an Integer-only backend so that aern2-mp can
   be used without MPFR.
 
@@ -46,9 +49,9 @@
     , mixed-types-num
   if flag(UseCDAR)
     cpp-options: -DUseCDAR
+    build-depends:
       cdar
   else
-    cpp-options: -DMPFRRounded
     build-depends:
       rounded == 0.1.*
 -- TODO
@@ -116,7 +119,6 @@
     AERN2.MP.BallSpec
     AERN2.MP.DyadicSpec
     AERN2.MP.FloatSpec
-    -- AERN2.MP.UseCDAR.FloatSpec
   build-depends:
     base == 4.*
     -- , mixed-types-num >= 0.3.1 && < 0.4
diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,5 +1,7 @@
 # Change log for aern2-mp
 
+* v 0.1.3.1 2018-11-21
+  * small fixes, mainly documentation
 * v 0.1.3.0 2018-11-20
   * only one MPFR backend - rounded
   * reduce backend-specific code
diff --git a/src/AERN2/MP/Float.hs b/src/AERN2/MP/Float.hs
--- a/src/AERN2/MP/Float.hs
+++ b/src/AERN2/MP/Float.hs
@@ -20,27 +20,18 @@
    -- * Precision operations
    module AERN2.MP.Precision
    -- * The type definition and basic operations
-#ifdef UseCDAR
-   , module AERN2.MP.Float.UseCDAR.Type
+   , module Type
    -- * Arithmetic operations
-   , module AERN2.MP.Float.UseCDAR.Arithmetic
+   , module Arithmetic
    , distUp, distDown, avgUp, avgDown
    -- * Conversions, comparisons and norm
-   , module AERN2.MP.Float.UseCDAR.Conversions
-#else
-    , module AERN2.MP.Float.UseRounded.Type
-    -- * Arithmetic operations
-    , module AERN2.MP.Float.UseRounded.Arithmetic
-    , distUp, distDown, avgUp, avgDown
-    -- * Conversions, comparisons and norm
-    , module AERN2.MP.Float.UseRounded.Conversions
-#endif
+   , module Conversions
    -- * Infix operators for up/down-rounded operations
-   , module AERN2.MP.Float.Operators
+   , module Operators
    -- * Constants such as NaN, infinity
-   , module AERN2.MP.Float.Constants
+   , module Constants
    -- * Tests
-   , module AERN2.MP.Float.Tests
+   , module Tests
    )
 where
 
@@ -50,18 +41,18 @@
 import AERN2.MP.Precision
 
 #ifdef UseCDAR
-import AERN2.MP.Float.UseCDAR.Type
-import AERN2.MP.Float.UseCDAR.Arithmetic
-import AERN2.MP.Float.UseCDAR.Conversions
+import AERN2.MP.Float.UseCDAR.Type as Type
+import AERN2.MP.Float.UseCDAR.Arithmetic as Arithmetic
+import AERN2.MP.Float.UseCDAR.Conversions as Conversions
 #else
-import AERN2.MP.Float.UseRounded.Type
-import AERN2.MP.Float.UseRounded.Arithmetic
-import AERN2.MP.Float.UseRounded.Conversions
+import AERN2.MP.Float.UseRounded.Type as Type
+import AERN2.MP.Float.UseRounded.Arithmetic as Arithmetic
+import AERN2.MP.Float.UseRounded.Conversions as Conversions
 #endif
 
-import AERN2.MP.Float.Operators
-import AERN2.MP.Float.Constants
-import AERN2.MP.Float.Tests
+import AERN2.MP.Float.Operators as Operators
+import AERN2.MP.Float.Constants as Constants
+import AERN2.MP.Float.Tests as Tests
 
 -- | Computes an upper bound to the distance @|x - y|@ of @x@ and @y@.
 distUp :: MPFloat -> MPFloat -> MPFloat
diff --git a/src/AERN2/MP/Float/UseRounded/Type.hs b/src/AERN2/MP/Float/UseRounded/Type.hs
--- a/src/AERN2/MP/Float/UseRounded/Type.hs
+++ b/src/AERN2/MP/Float/UseRounded/Type.hs
@@ -1,4 +1,3 @@
-{-# LANGUAGE CPP #-}
 {-# LANGUAGE DeriveGeneric, DeriveDataTypeable, StandaloneDeriving #-}
 {-|
     Module      :  AERN2.MP.Float.UseRounded.Type
diff --git a/src/AERN2/Utils/Bench.hs b/src/AERN2/Utils/Bench.hs
--- a/src/AERN2/Utils/Bench.hs
+++ b/src/AERN2/Utils/Bench.hs
@@ -14,7 +14,7 @@
 )
 where
 
-import Test.QuickCheck
+-- import Test.QuickCheck
 import Test.QuickCheck.Random (mkQCGen)
 import Test.QuickCheck.Gen (Gen(..))