title: Why an interface can not implement another interface?
body: <p>What I mean is:</p>
  
  <pre><code>interface B {...}
  
  interface A extends B {...} // allowed  
  
  interface A implements B {...} // not allowed
  </code></pre>
  
  <p>I googled it and I found <a href="http://www.coderanch.com/t/410331/java/java/interface-implements-interface" rel="noreferrer">this</a>:</p>
  
  <blockquote>
    <p><em><code>implements</code></em> denotes defining an implementation for the methods of an interface. However interfaces have no implementation so that's not possible.</p>
  </blockquote>
  
  <p>However, interface is an 100% abstract class, and an abstract class can implement interfaces (100% abstract class) without implement its methods. What is the problem when it is defining as "interface" ?</p>
  
  <p>In details,</p>
  
  <pre><code>interface A {
      void methodA();
  }
  
  abstract class B implements A {} // we may not implement methodA() but allowed
  
  class C extends B {
     void methodA(){}
  } 
  
  interface B implements A {} // not allowed. 
  //however, interface B = %100 abstract class B
  </code></pre>