Ltac method_call witness hist' result :=
repeat apply seq_assoc1;
match goal with 
   |- semax _ (PROPx _ (LOCALx ?Q (SEPx ?R))) 
            (Ssequence (Sset ?mt (Efield (Ederef (Etempvar ?x _)  _) _ _))
                 _) _  =>
    match Q with context [temp ?x ?x'] =>
     match R with context [object_mpred _ x'] =>
          let instance := fresh "instance" in let mtable := fresh "mtable" in
          unfold object_mpred; Intros instance mtable;
          forward;
          unfold object_methods at 1; 
          let sh := fresh "sh" in let r := fresh "r" in let t := fresh "t" in
          Intros sh r t;
          forward;
          forward_call witness;
          [ .. | try Intros result;
                  sep_apply (make_object_methods sh instance r t mtable); [ auto .. | ];
                  sep_apply (object_mpred_i hist' x' instance mtable);
                  deadvars; try clear dependent sh; try clear r; try clear t
           ]
    end end
end.

(* Specifications: *)
Lemma body_main: semax_body Vprog Gprog f_main main_spec.