Lower bounded wildcard not checked against upper bounded type parameter

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耶瑟儿～ 2021-02-20 03:01

I wonder why does this piece of code compile successfully?

Source code:

abstract class A
{
    public abstract  A


      
      
        
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                (楼主)
            
              
              
                2021-02-20 03:30
              

            
            
                        
Adding  to the first example doesn't add anything the compiler cares about. Remember you are saying "a type which is a supertype of M" if we are saying "M is a subtype of Number" and "the type is a supertype of M", we aren't actually saying if the type is a subtype of Number.

For a better example, have M be Integer and the variable be of type A