Proof using.
unfold not_empty.
intros.
break_match; congruence.
Qed.

(* Specifications: *)
Lemma haveNewEntries_true_intro :
forall st es,
es <> [] ->
(forall e, findAtIndex (log st) (maxIndex es) = Some e ->
eTerm e <> maxTerm es) ->
haveNewEntries st es = true.