Our professor is back from his trip to Europe. That's why we had the three-hour long seminar class again today. It is about rhetorical discourse relations, as I always blog about every Friday, but somehow, what I remember about the seminar today isn't about discourse relations, but about penguins.
Ah, because the professor used penguins for the examples.
Examples of what?
Examples of Defeasible Modus Ponens.
Defeasible Modus Ponens. It is the axiom that states that given the fact that one knows that p is one of the factors that may cause q, and you see p, then you may infer that q will happen.
So how does penguins enter the picture?
Let's say you have a penguin named Toto. Now, does Toto fly?
By applying Defeasible Modus Ponens on this problem, you get the following.
penguin(Toto) > bird(Toto)
bird(x) > fly(x)
penguin(y) > bird(y)
penguin(z) > ¬fly(z)
So what do these symbols mean?
First, if you have a bird, you can infer that birds fly. If you have a penguin, you can infer that penguins are birds. And if you have a penguin, you know that penguins cannot fly. Thus, the reason why it should be defeasible, is because, you cannot explain the fact that penguins do not fly. Therefore, Toto does not fly.
On a different note, I am irritated at something I have in my nose. I developed a pimple, right at the edge of my left nostril! And it hurts because every time I wipe my nose or whatever, it hurts! I cannot believe that at 23, I would still have a zit.