On the contrary, Bird(Penguin) does not allow concluding Flies(Penguin): even if the precondition of the default Bird(Penguin) is true, the justification Flies(Penguin) is inconsistent with what is known.
相反的，Bird（企鹅）不允许得出结论Flies（企鹅）:即使缺省的前件Bird（企鹅）是真的，论据Flies（企鹅）与已知相矛盾。