(1) Prove, that if more that (N + t)/2 processes start the crash-robust consensus algorithm (Algorithm 14 . 3) with input v, then a decision for v is taken in three rounds.
(2) Prove, that if more than (N - t)/2 processes start the algorithm with input v, then a decision for v is possible.
(3) Is a decision for v possible if exactly (N - t)/2 processes start the algorithm with input v?
(4) What are the bivalent input configurations of the algorithm?
Text Book: Introduction to Distributed Algorithms By Gerard Tel.