首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
A perennial problem in semantics is the delineation of its subject matter. The term meaning can be used in a variety of ways, an
A perennial problem in semantics is the delineation of its subject matter. The term meaning can be used in a variety of ways, an
admin
2016-10-21
18
问题
A perennial problem in semantics is the delineation of its subject matter. The term meaning can be used in a variety of ways, and only some of these correspond to the usual understanding of the scope of linguistic or computational semantics. We shall take the scope of semantics to be restricted to the literal interpretations of sentences in a context, ignoring phenomena like irony, metaphor, or conversational implicature.
A standard assumption in computationally oriented semantics is that knowledge of the meaning of a sentence can be equated with knowledge of its truth conditions: that is, knowledge of what the world would be like if the sentence were true. This is not the same as knowing whether a sentence is true, which is usually an empirical matter, but knowledge of truth conditions is a prerequisite for such verification to be possible. Meaning as truth conditions needs to be generalized somewhat for the case of imperatives or questions, but is a common ground among all contemporary theories, in one form or another, and has an extensive philosophical justification.
A semantic description of a language is some finitely stated mechanism that allows us to say, for each sentence of the language, what its truth conditions are. Just as for grammatical description, a semantic theory will characterize complex and novel sentences on the basis of their constituents: their meanings, and the manner in which they are put together. The basic constituents will ultimately be the meanings of words and morphemes. The modes of combination of constituents are largely determined by the syntactic structure of the language. In general, to each syntactic rule combining some sequence of child constituents into a parent constituent, there will correspond some semantic operation combining the meanings of the children to produce the meaning of the parent.
A corollary of knowledge of the truth conditions of a sentence is knowledge of what inferences can be legitimately drawn from it. Valid inference is traditionally within the province of logic as is truth and mathematical logic has provided the basic tools for the development of semantic theories. One particular logical system, first order predicate calculus(FOPC), has played a special role in semantics as it has in many areas of computer science and artificial intelligence. FOPC can be seen as a small model of how to develop a rigorous semantic treatment for a language, in this case an artificial one developed for the unambiguous expression of some aspects of mathematics. The set of sentences or well formed formulae of FOPC are specified by a grammar, and a rule of semantic interpretation is associated with each syntactic construct permitted by this grammar. The interpretations of constituents are given by associating them with set-theoretic constructions from a set of basic elements in some universe of discourse. Thus for any of the infinitely large set of FOPC sentences we can give a precise description of its truth conditions, with respect to that universe of discourse. Furthermore, we can give a precise account of the set of valid inferences to be drawn from some sentence or set of sentences, given these truth conditions, or given a set of rules of inference for the logic.
Some natural language processing tasks(e.g., message routing, textual information retrieval, translation)can be carried out quite well using statistical or pattern matching techniques that do not involve semantics in the sense assumed above. However, performance on some of these tasks improves if semantic processing is involved.
Some tasks, however, cannot be carried out at all without semantic processing of some form. One important example application is that of database query, of the type chosen for the Air Travel Information Service task. For example, if a user asks, "Does every flight from London to San Francisco stop over in Reykyavik?" then the system needs to be able to deal with some simple semantic facts. Relational databases do not store propositions of the form every X has property P and so a logical inference from the meaning of the sentence is required. In this case, every X has property P is equivalent to there is no X that does not have property P and a system that knows this will also therefore know that the answer to the question is no if a non-stopping flight is found and yes otherwise.
What is NOT discussed in the text?
选项
A、The knowledge of the truth conditions.
B、The development of semantic theory.
C、The applications of semantics.
D、First order predicate calculus.
答案
B
解析
细节题。A在第二段提及,文章最末两段提及C,D在文章倒数第三段出现,只有B没有提到。
转载请注明原文地址:https://kaotiyun.com/show/Aj7O777K
0
专业英语八级
相关试题推荐
Fromaveryearlyage,perhapstheageoffiveorsix,IknewthatwhenIgrewIshouldbeawriter.Betweentheages【M1】______
Fromaveryearlyage,perhapstheageoffiveorsix,IknewthatwhenIgrewIshouldbeawriter.Betweentheages【M1】______
Manythingsmakepeoplethinkartistsareweirdandtheweirdestmaybethis:artists’onlyjobistoexploreemotions,andyet
Whenaspeakerexpresseshisintentionofspeaking,suchasaskingsomeonetoopenthewindow,heisperforming______.
______isuniversallyconsideredasDanielDefoe’smasterpiece.
WhenthemeaningofsentenceAisincludedinsentenceB,thenwecansaythat
WhenIwasinmyearlyteens,Iwastakentoaspectacularshowonicebythemotherofafriend.Lookedroundattheluxuryof
WhenIwasinmyearlyteens,Iwastakentoaspectacularshowonicebythemotherofafriend.Lookedroundattheluxuryof
Educationistheprocessoflearningandknowing,whichisnotrestrictedtoourschooltext-books.Itisaholisticprocessan
A、Itissatisfying.B、Itisnotessential.C、Itistoomuch.D、Itisbarelyenough.D本题考查重要细节。根据句(7-1)、句(7—2)和句(7—3)可知,人们每天要摄取75
随机试题
根据《宪法》的规定,下列关于国家尊重和保障人权的说法正确的是()。
Ⅲ、Ⅳ期口腔癌患者放射治疗或手术治疗后,约有多少患者会出现头颈部的第二原发癌
A、四逆汤B、当归四逆汤C、回阳救急汤D、右归丸E、大建中汤四肢厥逆,恶寒蜷卧,呕吐不渴,腹痛下利,神衰欲寐,舌苔白滑,脉微细者。治疗应选用
王某租赁李某的店面经营饭店,因经营不善,拖欠租金达半年之久,李某和王某多次交涉未果,遂起诉到人民法院要求王某支付租金。在开庭的前一天李某开车遭遇车祸,抢救三天后无效死亡,人民法院裁定中止诉讼。十天后,李某唯一的继承人其儿子李小小(已成年)申请参加诉讼,人民
某建设项目投资构成中,设备及工、器具购置费为2000万元,建筑安装工程费为1000万元,工程建设其他费为500万元,预备费为200万元,建设期贷款1800万元,应计利息80万元,流动资金贷款400万元,则该建设项目的工程造价为()万元。【2004年
工程造价咨询企业资质有效期届满,需要继续从事工程造价咨询活动的,应当在资质有效期届满30日前向资质许可机关提出资质延续申请。准予延续的,资质有效期延续()年。
同定制造费用在三因素分析法下的能量差异,可以进一步分为()。
老年人多不饱和脂肪酸、单不饱和脂肪酸提供的能量占总能量的()比较合适。
林老师是一位经验丰富的英语老师,在教学过程中经常把学生按每组5__6人进行分组,小组成员围成一圈,开展话题或语言游戏活动等,从而发展学生的______。
A、Therightsofprivatebusinessownersshouldbeprotected.B、Thegovernmentshouldn’tinterfereinprivatebusiness.C、Politic
最新回复
(
0
)