Tree-Adjoining Grammars and Cross-Serial Dependencies in Dutch Embedded Clauses (was: Re: Unsupervised learning of natural languages)

On Thu, 3 Nov 2005 22:05:46 +0100, Henrik Theiling <theiling@...>
wrote:

>[snip]
> ... I never doubted they perform well in the given six languages.
>What I said was not about the number of languages they handle, but the
>structure of the languages.  The six given languages have a relatively
>context-free syntax structure with nicely embedded sub-phrases.  I
>merely said I would have been more surprised of a working algorithm if
>they had tested a more interesting language.  E.g.  Dutch, which has a
>very funny verb order in embedded phrases:
>
>   ... dat  ik jou zag lezen.
>       that I  you saw read
>       'that I saw you read.'
My library finally borrowed "Tree Adjoining Grammars: Formalisms,
Linguistic Analysis, and Processing", edited by Anne Abeille' and Owen
Rambow, CSLI Publlications (Center for the Study of Language and
Information, Stanford, California), P151.T75 2000, from the Indiana State
University Library for me.  (This is CSLI Lecture Notes #107; ISBN 1-57586-
252-2).

In their overview, the editors mention the Dutch sentence fragment:

"... omdat Wim Jan Marie de kinderen zag helpen leren zwemmen"

>The interesting part is that 'I saw' is one sub-phrase and 'you read'
>is another and that the final structure contains the subjects in a row
>followed by the verbs in the same order.  For arbitrarily deep
>nesting, this cannot be generated with a context-free grammar.
>Further, with a given context length, you can only generate a fixed
>number of reversals, so I think the grammar structure they are
>generating is just not suited for Dutch und thus for natural language
>in general.
They show how it can be handled by just one rule of a T.A.G., (_with_ _no_
_subsequent_ _transformations_, btw), and, like you, say it can't be
generated by context-free grammar.

> In Dutch you can have:
>
>     dat ik jou haar hem hoor vragen helpen koken.
>         A  B   C    D   a    b      c      d
>
>     that I hear you ask her help him cook.
>          A a    B   b   C   c    D   d
>
>This *is* quite an artificial example, but it illustrates the
>algorithmical problems I suspect.
Dang, I'm about to get timed out.

More later, maybe.

Tom H.C. in MI

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