Hint Resolve object_methods_local_facts : saturate_local.
Definition object_mpred (history: list Z) (self: val) : mpred :=
EX instance: object_invariant, EX mtable: val,
(object_methods instance mtable *
field_at Ews (Tstruct _object noattr) [StructField _mtable] mtable self*
instance history self).
Definition foo_invariant : object_invariant :=
(fun (history: list Z) p =>
withspacer Ews (sizeof size_t + sizeof tint) (2 * sizeof size_t) (field_at Ews (Tstruct _foo_object noattr)
[StructField _data] (Vint (Int.repr (2*fold_right Z.add 0 history)))) p
*  malloc_token Ews (Tstruct _foo_object noattr) p).
Definition foo_reset_spec :=
DECLARE _foo_reset (reset_spec foo_invariant).
Definition foo_twiddle_spec :=
DECLARE _foo_twiddle  (twiddle_spec foo_invariant).
Definition make_foo_spec :=
DECLARE _make_foo
WITH gv: globals
PRE [ ]
PROP () LOCAL (gvars gv)
SEP (mem_mgr gv; object_methods foo_invariant (gv _foo_methods))
POST [ tobject ]
EX p: val, PROP () LOCAL (temp ret_temp p)
SEP (mem_mgr gv; object_mpred nil p; object_methods foo_invariant (gv _foo_methods)).
Definition main_spec :=
DECLARE _main
WITH gv: globals
PRE  [] main_pre prog nil gv
POST [ tint ]
EX i:Z, PROP(0<=i<=6) LOCAL (temp ret_temp (Vint (Int.repr i))) SEP(TT).
Definition Gprog : funspecs :=   ltac:(with_library prog [
foo_reset_spec; foo_twiddle_spec; make_foo_spec; main_spec]).

Lemma body_foo_twiddle: semax_body Vprog Gprog f_foo_twiddle foo_twiddle_spec.