Hint Rewrite ptrofs_add_assoc1 : norm.

(* Specifications: *)
Lemma divide_add_align: forall a b c, Z.divide b a -> a + (align c b) = align (a + c) b.
Lemma force_val_e:
forall v, force_val (Some v) = v.
Lemma ptr_eq_True':
forall p, isptr p -> ptr_eq p p = True.