(* matchIndex *)
  Definition matchIndex_preserved st st' :=
    type st' = Leader ->
    (type st = Leader /\ matchIndex st' = matchIndex st /\ log st' = log st).Definition matchIndex_preserved_except_at_host h st st' :=
    type st' = Leader ->
    (type st = Leader /\
     forall h',
       h <> h' ->
       (assoc_default name_eq_dec (matchIndex st') h' 0) = (assoc_default name_eq_dec (matchIndex st) h') 0).

Theorem handleAppendEntries_term_votedFor : forall h st t n pli plt es ci st' ps h', handleAppendEntries h st t n pli plt es ci = (st', ps) -> votedFor st' = Some h' -> currentTerm st' = currentTerm st /\ votedFor st' = votedFor st.