}
@BIF static public EObject update_element(EProc proc, EObject tab, EObject key, EObject upd) {
ETable table = resolve(proc, tab, true);
ETuple2 t_upd = ETuple2.cast(upd);
ESeq s_upd = upd.testSeq();
if (table == null
|| (t_upd == null && s_upd == null)
|| !(table.type==am_set || table.type==am_ordered_set)) {