Definition on_path b o p :=
In b (concat (lookup_path_oram o p)).

Lemma disjoint_weaken2 : forall dlt l lst,
disjoint_list
(List.map block_blockid l)
(List.map block_blockid lst) ->
subset_rel dlt lst ->
disjoint_list
(List.map block_blockid l)
(List.map block_blockid dlt).