This macro returns the address of a folio function from a folio vector table.
Arguments
folio
A pointer to the folio item that contains the procedure. Use LookupItem() to get this pointer. For the item number of a folio (which you pass to LookupItem()), see the "Portfolio Items" chapter or call FindAndOpenFolio().
func
The index of the vector table entry for the procedure. This index (which is always a negative integer, because the table grows backward in memory) is listed in the header file for the folio that contains the procedure.