implicit super-interface in Java?
<p>So we all know that all classes implicitly extend Object. How about interfaces? Is there an implicit super-interface? I say there is. The following code compiles:</p>

<pre><code>java.io.Serializable s1 = null;
java.io.Serializable s2 = null;

s1.equals(s2);
</code></pre>

<p>The <code>equals</code> method is not declared in Serializable, but in Object. Since interfaces can only extend other interfaces, and Object is a class, not an interface, there must be some implicit interface that is being extended. And the <code>Object</code> class must then implicitly implement this implicit interface (wow, that was weird to write).</p>

<p>So, the question is, how correct is this?</p>
