Proof using.
intros. unfold handleAppendEntries, advanceCurrentTerm in *.
repeat break_match; find_inversion; auto.
Qed.

Lemma handleAppendEntries_type_term :
forall h st t n pli plt es ci st' ps,
handleAppendEntries h st t n pli plt es ci = (st', ps) ->
(type st' = type st /\ currentTerm st' = currentTerm st) \/
(type st' = Follower /\ currentTerm st' >= currentTerm st).