induction 1; intuition; simpl in *.
destruct (le_dec (datDepth t1) (datDepth t2)).
rewrite Max.max_r; eauto.
omega.
rewrite Max.max_l; omega.
Qed.

Lemma dat_better_bind_div2 : forall (A B : Set)(c1 : Comp B)(c2 : B -> Comp A) n t1 t2,
dat_correct_bind c1 c2 n t1 ->
dat_correct_bind2 c1 c2 (div2 n) t2 ->
dat_better t1 t2.