How interaction happens between bins with different coverpoints without help of cross coverage

How interaction happens between bins with different coverpoints without help of cross coverage
Ex coverpoint covpt1
bins avar1;
bins avar2;
coverpoint covpt2
bins bvar1;
bins bvar2;
without using cross coverage needs to interaction avar1 with bvar1 and bvar2, avar2 with bvar1 and bvar2 vice versa

please give me idea on this.

In reply to Subbi Reddy:

Can you explain why you can’t use cross coverage? Your requirement is the reason that cross coverage exists.

In reply to cgales:

This question asked in interview.

In reply to Subbi Reddy:

A cross is essentially a concatenation of coverpoints with permutations of all their bins.