Instance CompSpecs : compspecs. make_compspecs prog. Defined.
Definition Vprog : varspecs.  mk_varspecs prog. Defined.
Definition Gprog: funspecs := nil.
Definition Delta1 : tycontext :=
ltac:(let x := constr:(func_tycontext f_sumarray Vprog Gprog nil)
in let y := eval hnf in x
in exact y).

(* This example is from the "EX, Intros, Exists" chapter of the Verifiable C Reference Manual *)
Lemma exercise1:
let Delta := @abbreviate _ Delta1 in
forall sh p,
ENTAIL Delta,
EX x:Z,
PROP(0<=x) LOCAL(temp _i (Vint (Int.repr x)))
SEP (EX y:Z, !!(x<y) && data_at sh tint (Vint (Int.repr y)) p)
|-- EX u: Z,
PROP(0<u) LOCAL()
SEP (data_at sh tint (Vint (Int.repr u)) p).