Definition unOp_result_type op t :=
match op with
  | Cop.Onotbool =>match t with
                                | Tint _ _ _ => Tint IBool Signed noattr
                                | Tlong _ _ => Tint IBool Signed noattr
                                | Tpointer _ _ => Tint I32 Signed noattr
                                | Tfloat _ _ => Tint IBool Signed noattr
                                | Tarray _ _ _ => Tint IBool Signed noattr
                                | Tfunction _ _ _ => Tint IBool Signed noattr
                                | _ => Tvoid
                                end
  | Cop.Onotint => match t with
                                | Tint _ _ _ => Tint I32 Signed noattr
                                | Tlong _ _ => Tlong Signed noattr
                                | _ => Tvoid
                                end
  | Cop.Oneg => match t with
                           | Tint _ _ _ => Tint I32 Signed noattr
                           | Tlong _ _ => Tlong Signed noattr
                           | Tfloat _ _ => t
                           | _ => Tvoid
                           end
  | Cop.Oabsfloat => t
end.

Lemma typecheck_deref_sound: forall {CS: compspecs} Delta rho m e t pt, typecheck_environ Delta rho -> (denote_tc_assert (typecheck_expr Delta e) rho m -> tc_val (typeof e) (eval_expr e rho)) /\ (forall pt0 : type, denote_tc_assert (typecheck_lvalue Delta e) rho m -> is_pointer_type pt0 = true -> tc_val pt0 (eval_lvalue e rho)) -> denote_tc_assert (typecheck_lvalue Delta (Ederef e t)) rho m -> is_pointer_type pt = true -> tc_val pt (eval_lvalue (Ederef e t) rho).