Fixpoint id2pred_star   {cs: compspecs}
   (Delta: tycontext) (gz: globals) (sh: share) (v: val) (dl: list init_data) : environ->mpred :=
 match dl with
 | d::dl' => `(init_data2pred' Delta gz d sh v)
                   * id2pred_star Delta gz sh (offset_val (init_data_size d) v) dl'
 | nil => emp
 end.

Lemma init_data_size_pos : forall a, init_data_size a >= 0.