End VericSepLogic.
Check derives_extract_prop.
Print SepExpr.SepExpr.
Module Sep := SepExpr.Make VericSepLogic.

(* Specifications: *)
(*Definition if_then_else_isnil (b : forall (s: list val), {s=nil}+{s<>nil}) (m1 m2 : mpred) := if b then m1 else m2. *)
Lemma isnil: forall {T: Type} (s: list T), {s=nil}+{s<>nil}.
Hint Resolve link_local_facts : saturate_local.
Lemma link__local_facts:
forall x, link_ x |-- !! isptr x.