The Byzantine Generals Problem

The problem that every note faces is, how do i know what the next block is, and whether or not that's correct? If you're doing proof of state, you're relying on other authorities to tell you. But with the byzantine general's problem, that can be manipulated at any time. You might have multiple malicious signers that might want o fork, fork the network, or whatever. How do you know? Unless there is some sort of central co ordination, which in theByzantine general problem that there is not allowed to be,. Then then you can't do it with proof of state. You need some you need proof of work in order to figure out