Proof using.
intros.
match goal with
| [ |- context [ allEntries ?x ] ] =>
destruct (allEntries x)
using (update_elections_data_client_request_allEntries_ind ltac:(eauto))
end; intuition.
Qed.

Lemma handleClientRequest_preservers_log :
forall h st client id c out st' ms e,
handleClientRequest h st client id c = (out, st', ms) ->
In e (log st) ->
In e (log st').