Cover bins for sweeping an event with respect to another event for -N to +N clocks

How to write a functional cover bin which will cover sweeping of an event with respect to other event for -N to +N clock cycles

For example, I have a signal A which will assert at 10th clock cycle so I want to go back to 3 cycles before and after it (assume N=3 here). So I want to make sure event B has occurred at 7th and 13th clock cycles.