# What is a BDD(0)?

Good evening,

I was practising the Constrain-algorithm recently and I wasn't able to figure out what is meant by BDD(0) on this slide:

The slide with the Quartz-code on it also uses a BDD(1), but I can't find an explanation for either of the terms anywhere in the slides.

A short explanation would be great, thanks in advance.

+1 vote
It refers to the False/True leaves. BDD(0) = False-leaf. BDD(1) = True-leaf.
by (2.4k points)
Ok, in this case I must have done something wrong elsewhere. But it is a bit confusing, that sometimes it just says "1" (same slide: Constrain(1, φ) = φ), and other times "BDD(1)", so I thought there must be a difference. And then, slide 108 in this chapter, it says "Exists(L, φ) = φ (L must be true here)", so that's just the same, right? L should be 1 here as well.

Thanks anyway for the quick answer, I will try it again, maybe I can figure it out and find my mistake, now.
Yes, that's right. It also says L is a leaf. So it means "Exists(BDD(1), φ) = φ"
Thank you very much, I think I got it now. No idea where my mistake was, but anyways, it works.