diff --git a/egison.cabal b/egison.cabal
--- a/egison.cabal
+++ b/egison.cabal
@@ -1,5 +1,5 @@
 Name:                egison
-Version:             4.2.0
+Version:             4.2.1
 Synopsis:            Programming language with non-linear pattern-matching against non-free data
 Description:
   An interpreter for Egison, a **pattern-matching-oriented**, purely functional programming language.
@@ -12,41 +12,6 @@
   An non-free data type is a data type whose data have no canonical form, a standard way to represent that object.
   It enables us to write elegant programs.
   .
-  /Twin Primes/
-  .
-  We can use pattern-matching for enumeration.
-  The following code enumerates all twin primes from the infinite list of prime numbers with pattern-matching!
-  .
-  <<https://raw.githubusercontent.com/egison/egison/master/images/twin-primes-w700.png>>
-  .
-  /Poker Hands/
-  .
-  The following code is the program that determines poker-hands written in Egison.
-  All hands are expressed in a single pattern.
-  .
-  <<https://raw.githubusercontent.com/egison/egison/master/images/poker-hands-w700.png>>
-  .
-  /Mahjong/
-  .
-  We can write a pattern even against mahjong tiles.
-  We modularize patterns to represent complex mahjong hands.
-  .
-  <<https://raw.githubusercontent.com/egison/egison/master/images/mahjong-w700.png>>
-  .
-  /Graphs/
-  .
-  We can pattern-match against graphs.
-  We can write program to solve the travelling salesman problem in a single pattern-matching expression.
-  .
-  <<https://raw.githubusercontent.com/egison/egison/master/images/salesman-w700.png>>
-  .
-  Aren't thsese exciting?
-  We can run these demonstrations on our website!
-  Please view and try more demonstrations!
-  .
-  <http://www.egison.org>
-  .
-  Egison makes programming dramatically simple.
   Please enjoy Egison!
 Homepage:            http://www.egison.org
 License:             MIT