mainproc: proc options(main) reorder;
 dcl list_ptr ptr            init (sysnull());
 dcl list_top ptr            init (sysnull());
 dcl list_end ptr            init (addr(list_top));
 dcl i        fixed bin (31);

 dcl 1 list based(list_ptr),
       2 list_nxt  ptr            init (sysnull()),
       2 list_data fixed bin (31) init (i);

 /*
 * Allocate the list
 */
 do i = 1 to 4;
   alloc list;
   list_end -> list_nxt = list_ptr;
   list_end             = list_ptr;
 end;

 /*
 * Print the list
 */
  do list_ptr = list_top repeat list_nxt
                        while(list_ptr ^= sysnull());
   put skip list(list_data);
 end;
 end mainprog;