oops, I got carried away with the key idea. I'll definitely go with omitting the an-3 column as you suggested, but have one more question about the drawn arrows. since i'm skipping the an-3 column, will I completely ignore the arrow drawn from bn-3 to cbn-3? Just want to make sure I don't need to draw the arrow from bn-3 to the ellipsis. Thanks so much, Lindy!