Hint Rewrite globvars2pred_unfold : norm.
Hint Rewrite @exp_trivial : norm.

Lemma eval_var_isptr:
forall Delta t i rho,
tc_environ Delta rho ->
((var_types Delta) ! i = Some t \/
(var_types Delta)!i = None /\
(glob_types Delta) ! i = Some t) ->
isptr (eval_var i t rho).