Proof using.
induction l; intros; simpl in *; intuition; subst;
repeat break_match; subst; simpl in *; intuition eauto;
congruence.
Qed.

Lemma contradicting_leader_logs_empty :
forall net nodes t e,
contradicting_leader_logs net nodes t e = [] ->
forall h,
In h nodes ->
contradicting_leader_logs_on_leader (leaderLogs (fst (nwState net h))) t e = [].