No account? Create an account

## Bioinformatics Part Two and Wicked Fleas

First off, the second part of the title: in CIS 730: Principles of Artificial Intelligence, we are starting to go through First-Order Logic (FOL) and FOL theorem proving by resolution. One year (2002, IIRC) I put up the proverb:
Only the wicked flee when no one pursueth.

and asked the students to translate this into FOL. e.g.,
\forall x, y .  Flees(x, y) & \neg \exists z . Pursues(z, x) \rightarrow isWicked(x)

Every now and then I get a student who hears the above proverb and defines isWickedFlea.

When the chuckles subsided, a couple of things occurred to me.

One was that archaic forms such as "pursueth" were as alien to some international students (e.g., those from India and China) and about as unrecognizable as cursive handwriting.

A second revelation, the main topic of this post, was that the entropy of typos and word sense and spelling ambiguities is variable and not easily constant-bounded. The predictive entropy would be one interesting effect to quantitatively measure where possible. Someday, this might aid in recognition of double entendres and intended puns.

But how might one use the information in general? Specifically, how would one hook a quantitative analyzer of text or speech-based discourse to a training corpora, and discover the highest-impact typos?

--
Banazir

Sep. 25th, 2004 07:57 am (UTC)
\exists x \setof students . isme(x) \rightarrow loves(FOL)

loves(I, lambda)

Sep. 25th, 2004 08:49 am (UTC)
Hey, listen up, buddy!
(Puts on professor hat)

\E x . P(x) & Q(x)
\A x . P(x) => Q(x)
are the usual forms. The above is tautological (trivially valid) in any possible worlds system where you are not alone, because all you have to do to satisfy the implicative statement

isme(x) => SOMETHING

is to have !isme(x) be true. i.e., there's someone who is not you.

Take a look at the FOL lecture slides of Stuart Russell. At least in the Russell and Norvig 1st edition notes that he had up on the AIMA page, equivalent examples were given.

--
Banazir

Sep. 25th, 2004 08:59 am (UTC)
Re: Hey, listen up, buddy!
oh, the second line was unrelated to the first
and on the first i shouldve said something like

"\forall x \setof students . isme(x) \rightarrow lovesFOL(x)"

the other version was more lisp-like

sorry i had just woken up when i posted the comment.
but thanks for the info

Sep. 25th, 2004 09:01 am (UTC)
Re: Hey, listen up, buddy!
btw i learned it from W.V.O Quine, who uses a bit more antiquated notation

Sep. 25th, 2004 10:27 am (UTC)
Quinings are the shiznit
(I have a running bet with that I can say "the shiznit" with a straight face. I believe this counts; I may need to use the miniDV camcorder to provide video evidence, though.)

Thanks for the reference, but I was referring just to the first sentence, not the second at all. Implications inside existential quantifiers are often tautological, which is why classical syllogism usually follows the forms I listed. (That goes for your corrected Q(x) form too.)

What exactly is the constant \lambda? The whole of the calculus? If so, you're looking at a second-order logic. :-)

--
Banazir

Sep. 25th, 2004 10:33 am (UTC)
Re: Quinings are the shiznit
i wont respond for risk of incompleteness..

--t-b--

Sep. 25th, 2004 04:51 pm (UTC)
ENTscheidunsproblem
How... Godelian. :-P

--
Banazir