Regarding Method Overriding / Polymorphism SystemVerilog

Yes but isn’t the value of ‘a’ mutually exclusive ? I don’t understand why 2 a’s are created when I have constructed only one object which happens to be the derived class. And that value in the derived class overrides inherited value as per the LRM.

When you say “2 classes become one” shouldn’t the value in the derived class override the value inherited from base class ?