Assignment funda not clear

[Rajesh k Jha]

This programme is correct and compiles and runs fine
but i want to know how things are being assigned to each other(in line 1,2,3,4,5,6,7)

Can somebody please explain how its all is happening,as this is something very confusing to me

    
interface Min{}
      
      class A{}
        
     class B extends A implements Min{}
      
      class C extends B{}
      
       public class CCExp{
           public static void main(String args[]){
              A a=new A();
               B b=new B();
                C c=new C();
             Min m=null;//1
               b=(C)m;//2
               m=(Min)b;//3
               A a2=(A)m;//4
                B b2=(B)a2;//5
               Min m2=(C)b2;//6
                C c2=(C)m2;//7
       }
      

[Sebastian Janisch]

Don't cross-post. And even more don't cross post in the same forum, that makes it even worse ...