Two questions about defining class, pls help me

Question

Hi, guys. I'm green hand and here are two questions puzzled me several days.
We know such example as below is a case of cyclic inheritance
class Base extends Base{     
But I can't figure out why below is a case of cyclic inheritance too
class Base{
class Derived extends Base{
class Base{
I can't find the clue of cyclic inheritance. It's quite different from the case that a class extends itself or its subclass.
Another question is why the inner class can't have the same name of outer?
class Base{
class Base{          
The compiler says Base is already defined in unnamed package. As it says, the inner class is defined in the
unnamed package, but we know below is correct.
class Base{
class Basic{          
class Derived {
class Basic{
We know it's correct. But as the compiler says above, the different two inner class Basic are both defined in the
unnamed package. Why it's valid and why above is invalid?

Answer 1

Hi,
Can you tell us which product (s) you are referring to ? Can you also tell us the nature of your business requirements so that we can offer some suggestions ?
Regards,
Sandeep