the fact that like you can have a algorithm that say solves a a problem all possible graphs no matter which graph you see even graphs you will never be able to see you can still prove it's going to work and give you the right answer for this graph okay on all possible instances okay now a typical theorem from lower bounds will say something like here is a proof P that this problem can't be solved on all possible by all above two albums of some class some weak class of algorithms that I've sort of box over here and I can