Hint Rewrite sem_cast_pointer2' using (try apply Coq.Init.Logic.I; try assumption; reflexivity) : norm.

(* Specifications: *)
Lemma sem_cast_pointer2:
forall v t1 t2 t3 t1' t2',
t1' = Tpointer t1 noattr ->
t2' = Tpointer t2 noattr ->
tc_val (Tpointer t3 noattr) v ->
force_val (sem_cast t1' t2' v) = v.
Lemma force_eval_var_int_ptr :
forall  {cs: compspecs}  Delta rho i t,
tc_environ Delta rho ->
tc_lvalue Delta (Evar i t) rho |--
!! (force_val
match eval_var i t rho with
| Vptr _ _ => Some (eval_var i t rho)
| _ => None
end = eval_var i t rho).