Inductive sublist {A} : list A -> list A -> Prop :=
| sublist_nil : sublist nil nil
| sublist_cons a l1 l2 : sublist l1 l2 -> sublist (a :: l1) (a :: l2)
| sublist_drop a l1 l2 : sublist l1 l2 -> sublist l1 (a :: l2).Inductive sublist {A} : list A -> list A -> Prop :=
| sublist_nil : sublist nil nil
| sublist_cons a l1 l2 : sublist l1 l2 -> sublist (a :: l1) (a :: l2)
| sublist_drop a l1 l2 : sublist l1 l2 -> sublist l1 (a :: l2).Inductive sublist {A} : list A -> list A -> Prop :=
| sublist_nil : sublist nil nil
| sublist_cons a l1 l2 : sublist l1 l2 -> sublist (a :: l1) (a :: l2)
| sublist_drop a l1 l2 : sublist l1 l2 -> sublist l1 (a :: l2).Inductive sublist {A} : list A -> list A -> Prop :=
| sublist_nil : sublist nil nil
| sublist_cons a l1 l2 : sublist l1 l2 -> sublist (a :: l1) (a :: l2)
| sublist_drop a l1 l2 : sublist l1 l2 -> sublist l1 (a :: l2).

Lemma sublist_In {A} (a : A) l1 l2 : sublist l1 l2 -> In a l1 -> In a l2.