Introduction to CL (LING 185B)
Marcus Kracht
Spring 2006
Time: To be discussed
Short Description of the Course
Given a sentence, say The cat is on the mat how is it
that we can find what it means? And how can we know whether
or not it is true? Several proposals exist. One is Montague
Grammar, and another one is Discourse Representation Theory
(DRT). The idea behind DRT is that meanings are simply
expressions in predicate logic such as be-on(x,y),
and the task is to assemble these formulae into a structure
(a DRS) as well as to come up with the right choice of variable.
DRS assumes that the choice of variables is given by the parser.
The course will present a third theory that I have developed
over the years. It builds on top of DRT by providing systematic
algorithms to choose variables. This means that this job is
taken away from the parser. These algorithms are very fast, since
they use only unification. The theory uses both word order and
morphological information, and has been developed with an eye
to morphologically rich languages. Thus, the theory is interesting
both from a linguistic and a computational perspective, and the
course will highlight both.
To Read About the Theory
The theory is documented in the manuscript
Agreement Morphology, Argument Structure and Syntax.
This explains in full length everything about the theory.
Parts of it are not yet finished, and I would be particularly
glad about feedback, whatever it may be.
To See It At Work
Since cheking the theory and seeing how it works requires
plenty of tedious calculations, I have decided to write a
program that can do this sort of thing. It is almost complete;
I have not implemented higher order merge, but we will not
use it much anyway. (I hope to make some progress in the next
weeks.) You can play with it without installing any software,
provided you are happy with my dictionary (there is only one
at the moment). For the course it would be best to install
it on your machines.
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The page
Referent Systems contains a program written in OCaML
that you can use to play with the theory. To run the software,
you minimally need OCaML and LaTeX. If you want a graphical
user interface, you may want to use Tcl/Tk as well.
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OCaML can be obtained for free by download from
INRIA.
You will be given directives for implementations on various
platforms, and there is a host of useful material that can
be accessed as well. The current version is 3.09.1 (January
2006).
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LaTeX can be downloaded from
LaTeX Project. It is free and useful also for other purposes
(such as writing papers ...)
Assignments
There will be no weekly assignments. Instead, I encourage
you to pick a topic during the course on which you want
to work. This can be either some programming task or some
theoretical problem. Here is a
list of potential topics.