Specify implement interface on derived class when base class implements it abtract
<p>I was wondering if there are any (runtime) difference if I implement an interface on a derived class if the base abstract class implements it already abstract:</p>

<pre><code>public interface IFoo
{
  void Bar();
}

public abstract class Base : IFoo
{
  public abstract void Bar();
}

public class Derived : Base, IFoo // does this make any difference?
{
  public override void Bar()
  {
    // do something
  }
}
</code></pre>

<p>Is there any difference writing the "implemention" <code>IFoo</code> on <code>Derived</code> for example when I check if an instance implements an interface at runtime etc.?</p>