Lemma handleRequestVoteReply_type : forall h st h' t r st', handleRequestVoteReply h st h' t r = st' -> (type st' = type st /\ currentTerm st' = currentTerm st) \/ (type st' = Follower /\ currentTerm st' > currentTerm st) \/ (type st = Candidate /\ type st' = Leader /\ currentTerm st' = currentTerm st).