def inf_loop_multiple_back_edge(rec):
 while True:
  rec.mark('yield')
  (yield)
  p = rec('p')
  if p:
   rec.mark('bra')
   pass

def inf_loop_multiple_back_edge ( rec ) : while True : rec . mark ( 'yield' ) ( yield ) p = rec ( 'p' ) if p : rec . mark ( 'bra' ) pass
test to reveal bug of invalid liveness when infinite loop has multiple backedge .