A common feature of recent unificationbased g r a m m a r formalisms is that they give the user the ability to define his own structures. However, this possibility is mostly limited and does not include nonmonotonic operations. In this paper we show how nonmonotonic operations can also be user-defined by applying default logic (Reiter, 1980) and generalizing previous results on nonmonotonic sorts (Young and Rounds, 1993).
Suppose we have a feature system, and we wish to add default values in a well-defined way. We might start with Kasper-Rounds logic, and use Reiter's example to form it into a default logic. Giving a node a default value would be equivalent to saying "if it is consistent for this node to have that value, then it does." Then we could use default theories to describe feature structures. The particular feature structure described would be the structure that supports the extension of the default theory. This is, in effect, what the theory of nonmonotonic sorts gives you. This...
A prerequisite to a theory of the way agents understand speech acts is a theory of how their beliefs and intentions are revised as a consequence of events. This process of attitude revision is an interesting domain for the application of nonmonotonic reasoning because speech acts have a conventional aspect that is readily represented by defaults, but that interacts with an agent's beliefs and intentions in many complex ways that may override the defaults.
Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: HAJEK-RENYI-TYPE INEQUALITY FOR SOME NONMONOTONIC FUNCTIONS OF ASSOCIATED RANDOM VARIABLES
This paper shows how DATR, a widely used formal language for lexical knowledge representation, can be used to define an I_TAG lexicon as an inheritance hierarchy with internal lexical rules. A bottom-up featural encoding is used for LTAG trees and this allows lexical rules to be implemented as covariation constraints within feature structures. Such an approach eliminates the considerable redundancy otherwise associated with an LTAG lexicon.
The essays collected in this volume represent work carried out over a
period of more than ten years on a variety of problems in artificial intelligence,
the philosophy of mind and language, and natural-language
semantics, addressed from a perspective that takes as central the use of
formal logic and the explicit representation of knowledge.
We introduce three new techniques for statistical language models: extension modeling, nonmonotonic contexts, and the divergence heuristic. Together these techniques result in language models that have few states, even fewer parameters, and low message entropies.
Obtaining high-quality machine translations is still a long way off. A postediting phase is required to improve the output of a machine translation system. An alternative is the so called computerassisted translation. In this framework, a human translator interacts with the system in order to obtain high-quality translations. A statistical phrase-based approach to computer-assisted translation is described in this article. A new decoder algorithm for interactive search is also presented, that combines monotone and nonmonotone search. ...
We present an algorithm for generating strings from logical form encodings that improves upon previous algorithms in that it places fewer restrictions on the class of grammars to which it is applicable. In particular, unlike an Earley deduction generator (Shieber, 1988), it allows use of semantically nonmonotonic grammars, yet unlike topdown methods, it also permits left-recursion. The enabling design feature of the algorithm is its implicit traversal of the analysis tree for the string being generated in a semantic-head-driven fashion. ...