inheritance - Why does java gives an error while just writing package-private member of class in subclass -

i have 2 classes r , t in package accessing package-private member of class r in t r.x; gives error while works system.out.println(r.x); why ? know r.x; useless still curious why so.

adding code sample

package test;   public class main {   public static void main(string[] args) throws interruptedexception {     r obj=new r();     system.out.println("calling public method of z"+obj.getz());     system.out.println("calling protected method of y"+obj.gety());     system.out.println("calling static public member of z"+r.z);     system.out.println("calling static protected member of y"+r.y);     t.x;//this here shows error in eclipse      r.z;      system.out.println(t.x); // works fine }  }  package test;  public class t {      public final static int z=1;     protected static int y=2;     static int x=3;      public int getz(){         return z;     }      protected int gety(){         return y;     }      private int getx(){         return x;     } }    package test;    public class r extends t{     } 

the private data members not accessible outside class declared/defined if access private data members happens class within same package. refer access rules data members here http://javapapers.com/core-java/access-modifiers-in-java-explain/.