I understand perfectly but it doesn’t make sense. It’s simple, non-intuitive math and I can see 2 answers and it probably is one of those. Hopefully that’s all I need to know, but I won’t find out right now.

Or maybe it’s (the missile knows)… “the triangle knows where_it_is at all times. It knows this because it knows where_it_is-not. By subtracting where_it_is from where_it_is-not…”