intros st p.
generalize dependent st.
induction p.
+ intros st f l Corr Pref.
unfold addToTree.
destruct st.
- auto.
- exfalso.
apply corrEmptyLeaf in Corr.
inversion Corr; clear Corr.
subst.
pose proof Pref [] as Contra; clear Pref.
eapply Contra; clear Contra.
* left; auto.
* instantiate (1 := []). instantiate (1 := []). auto.
- simpl. auto.
+ intros.
destruct st; destruct a; simpl; auto.
- rewrite refineFunCorrect.
apply IHp.
- rewrite refineFunCorrect; apply IHp.
- exfalso. eapply corrEmptyLeaf in Corr; inversion Corr; subst; clear Corr.
pose proof (Pref []).
eapply H.
- subst; left; auto.
- simpl. instantiate (2:= []); rewrite app_nil_r. instantiate (1 := Left ::p); auto.
- exfalso. eapply corrEmptyLeaf in Corr; inversion Corr; subst; clear Corr.
pose proof (Pref []).
eapply H.
- subst; left; auto.
- simpl. instantiate (2:= []); rewrite app_nil_r. instantiate (1 := Right ::p); auto.
- rewrite refineFunCorrect; apply IHp.
- rewrite refineFunCorrect; apply IHp.
Qed.

Lemma addToTreeCorrect2 : forall (st : SeedTree) (p : SplitPath)
(f : SplitPath -> RandomSeed)
(l : list SplitPath) (Corr : correspondingSeedTree l f st)
(Pref : forall p', In p' l -> (forall p1 p2, p ++ p1 = p' ++ p2 -> False)),
forall p' seed, varySeed' st p' = Some seed ->
varySeed' (addToTree st p f l Corr Pref) p' = Some seed.