Section NextIndexSafety.
Context {orig_base_params : BaseParams}.
Context {one_node_params : OneNodeParams orig_base_params}.
Context {raft_params : RaftParams orig_base_params}.
Context {aersi : append_entries_reply_sublog_interface}.
Context {si : sorted_interface}.
Proof using.
unfold raft_net_invariant_init, nextIndex_safety.
intros.
discriminate.
Qed.
Definition nextIndex_preserved st st' :=
(type st' = Leader ->
type st = Leader /\
maxIndex (log st) <= maxIndex (log st') /\
nextIndex st' = nextIndex st).
Proof using.
unfold getNextIndex, nextIndex_preserved in *.
intuition.
repeat find_rewrite.
auto.
unfold assoc_default in *.
specialize (H h').
break_match.
- eauto using le_trans.
- lia.
Qed.

Theorem handleClientRequest_nextIndex_preserved :
forall h st client id c out st' ps,
handleClientRequest h st client id c = (out, st', ps) ->
nextIndex_preserved st st'.