Definition inj_on_list {A B} (l : list A) (f : A -> B) :=
forall x y, In x l -> In y l -> f x = f y -> x = y.
Definition subset_rel {X} (sub lst : list X) : Prop :=
forall x,
In x sub ->
In x lst.
(*** NoDup general lemmas ***)

Lemma disjoint_dlt : forall o lvl dlt lst p,
NoDup (List.map block_blockid lst) ->
subset_rel dlt lst ->
disjoint_list
(List.map block_blockid (get_all_blks_tree o))
(List.map block_blockid lst) ->
disjoint_list
(List.map block_blockid (get_all_blks_tree (up_oram_tr o lvl dlt p)))
(List.map block_blockid (remove_list_sub eqb dlt lst)).