README.md in haskell-0.0.2 vs README.md in haskell-0.0.3

@@ -1,19 +1,22 @@
 # Ruby with Type.
 
-```rb
+Matz has mentioned Ruby3.0 with static type at some confluences. But almost all rubyists(include me) are not sure how typed Ruby is.
 
+But it's worth thinking more. This gem is kind of trial without so much side-effect.
+
+```rb
 require 'haskell'
 
-# Ruby 2.1.0+
+# ex1: (Ruby 2.1.0+)
 class MyClass
-    type Numeric >= Numeric >= Numeric, def sum(x, y)
+  type Numeric >= Numeric >= Numeric, def sum(x, y)
     x + y
   end
 
   type Numeric >= Numeric >= Numeric, def wrong_sum(x, y)
-  'string'
+    'string'
   end
 end
 
 MyClass.new.sum(1, 2)
 #=> 3
@@ -22,19 +25,66 @@
 #=> ArgumentError: Wrong type of argument, type of "str" should be Numeric
 
 MyClass.new.wrong_sum(1, 2)
 #=> TypeError: Expected wrong_sum to return Numeric but got "str" instead
 
-# Ruby 1.8.0+
+
+# ex2: (Ruby 2.1.0+)
+class People
+  type People >= Any, def marry(people)
+    # Your Ruby code as usual
+  end
+end
+
+People.new.marry(People.new)
+#=> no error
+
+People.new.marry('non people')
+#=> ArgumentError: Wrong type of argument, type of "non people" should be People
+
+
+# ex3: (Ruby 1.8.0+)
 class MyClass
   def sum(x, y)
     x + y
   end
   type Numeric >= Numeric >= Numeric, :sum
 end
 ```
 
+## Feature
+### Typed method can coexist with non-typed method
+
+```ruby
+# It's totally OK!!
+class MyClass
+  type Numeric >= Numeric >= Numeric, def sum(x, y)
+    x + y
+  end
+
+  def wrong_sum(x, y)
+    'string'
+  end
+end
+```
+
+### Duck typing
+
+```ruby
+
+class MyClass
+  type Any >= Numeric, def foo(any_obj)
+    1
+  end
+end
+
+# It's totally OK!!
+MyClass.new.foo(1)
+# It's totally OK!!
+MyClass.new.foo('str')
+```
+
 ## Installation
 
 Add this line to your application's Gemfile:
 
 ```ruby
@@ -47,32 +97,16 @@
 
 Or install it yourself as:
 
     $ gem install haskell
 
-## More example
-```ruby
-class People
-  type People >= Any, def marry(people)
-    # Your Ruby code as usual
-  end
-end
-
-People.new.marry(People.new)
-#=> no error
-
-People.new.marry('non people')
-#=> ArgumentError: Wrong type of argument, type of "non people" should be People
-
-```
-
 ## Contributing
 
 1. Fork it ( https://github.com/[my-github-username]/haskell/fork )
 2. Create your feature branch (`git checkout -b my-new-feature`)
 3. Commit your changes (`git commit -am 'Add some feature'`)
 4. Push to the branch (`git push origin my-new-feature`)
 5. Create a new Pull Request
 
 
 ## Credits
-[@chancancode](https://github.com/chancancode) first brought this to my attention.
+[@chancancode](https://github.com/chancancode) first brought this to my attention. I've stolen some idea from him.