Definition top_more (a b c d : Z) :=
  (c <= a)%Z /\ (d < b)%Z \/ (c < a)%Z /\ (d <= b)%Z.

Lemma top_more_5' : forall a b c d : Z, (0 < a + b)%Z -> (a + b + (c - a) + (d - b) < a + b + c + d)%Z.