Complex sentence: 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.
Split into simpler sentences: On the contrary, Bird (Penguin) does not allow concluding Flies (Penguin). Indeed, even if the precondition of the default Bird (Penguin) is true, the default rule cannot be applied because its justification Flies (Penguin) is inconsistent with what is known.