Definition lifted_nextIndex_safety net : Prop :=
    forall h h',
      type (snd (nwState net h)) = Leader ->
      pred (getNextIndex (snd (nwState net h)) h') <= maxIndex (log (snd (nwState net h))).

(* Specifications: *)
Lemma lifted_nextIndex_safety_invariant : forall (net : @network _ raft_msg_refined_multi_params), msg_refined_raft_intermediate_reachable net -> lifted_nextIndex_safety net.