AS3：一个接口实现另一个接口

Question

I am so surprised that this code compiles, but what does it mean ?

public interface IBar {}
public interface IFoo implements IBar {}

Answer 1

It can't be compiled because interface can't implement the other interface but can extends it:

public interface IFoo extends IBar {}

Your code must leads to error:

1084: Syntax error: expecting leftbrace before implements.