语义转换--直接指称语义到接续指称语义

指称语义分为直接指称语义和接续指称语义,其中后一种语义描述的难度较大,给出了直接指称语义描述到接续指称语义描述的转换方法,这就使得这种语义转换的自动化成为可能．转换算法揭示了直接指称语义与接续指称语义之间的内在关系,同时也提供了写接续指称语义描述的有效方法．当需要检验同一种语言的直接指称语义描述和接续指称语义描述是否等价时,提供的技术是很有用的。     

对象描述语言及其指称描述

在面向对象的软件构造中,对象被视为软件系统的基本构件．本文提出对象规范描述语言ＯＤＬ（ｏｂｊｅｃｔｄｅｓｃｒｉｐｔｉｏｎｌａｎｇｕａｇｅ）,并给出其主要结构的ＳＯＰ指称描述．ＳＯＰ演算的理论范集给出对象的形式描述．ＳＯＰ理论范集反映了对象的封装性,在这样的逻辑框架下,对象的属性（结构）和动作（行为）得以统一．对象聚合提供了由已有对象描述构造复杂对象描述的机制;而继承则可以扩充给定的对象描述并保持原描述的特性．此外,本文还区分了继承和子类这２个相似而又不尽相同的概念.     

Formal Features of Compositionality

We consider two formalisations of the notion of a compositionalsemantics for a language, and find some equivalent statements in termsof substitutions. We prove a theorem stating necessary and sufficientconditions for the existence of a canonical compositional semanticsextending a given partial semantics, after discussing what features onewould want such an extension to have. The theorem involves someassumptions about semantical categories in the spirit of Husserl andTarski.     

接续到直接的指称语义转换

接续和直接指称语义之间的转换的主要难点在于不保函数基调.基于Monad思想推导出的接续语义函数和直接语义函数之间的关系,给出了基于规约的从接续指称语义描述形式到直接指称语义描述形式的转换技术,分别考虑了接续函数在不同情形下的处理.最后给出了转换算法的Haskell实现系统,验证了转换的可行性.     

Denotational semantics of communicating processes based on a language for applicative multiprogramming

The denotational semantics of a simple language for describing tightly coupled ‘synchronous’ systems is defined by translating it into a language for applicative multiprogramming. The applicative language has originally been developed for describing nondeterministic stream-processing functions and loosely-coupled systems of communicating processes. Nevertheless, it can be used after very slight generalizations as a semantic target language for defining the meaning of programs representing tightly-coupled, synchronous systems.     

藏文语义词典建设中语义关系抽取方法的研究

研究语义是当前人工智能、语义网、语义词典等研究领域的热点,它可以有效支持机器翻译和自然语言处理等技术.文章根据藏文独特的文法特性,运用藏文逻辑格和计算语言学知识,在保留藏文原有特点的基础上,为藏文语义关系抽取方法建立较完整的语义场,以此为藏文语义词典建设提供了基础性构建方法.     

Continuations Revisited

To introduce the republication of his joint 1974 paper with Christopher Strachey, Continuations: A Mathematical Semantics for Handling Full Jumps, the author recalls earlier unsuccessful struggles which culminated eventually in the almost instantaneous insight for their discovery of continuations in 1970.     

补偿通信顺序进程的扩展及失败发散语义

补偿通信顺序进程(cCSP)是通信顺序进程用于长事务建模的扩展,可用来描述服务计算中的编制程序,比如WS-BPEL程序。目前,cCSP只有操作语义和基于迹的指称语义,对死锁和发散行为的推理支持不够。本文扩展了cCSP,引入新的组合操作子,给出扩展cCSP的失败发散语义;并根据该语义,给出新引入组合操作子的重要代数规则,用于语义的理解和佐证。最后,给出一个案例描述用于展示扩展cCSP。     

一个面向语义的解释器自动生成技术

本文给出从指称语义自动生成解释器后端的一种技术.解释器被表示成PASCAL_like形式.     

Denotational semantics of a para-functional programming language

Apara-functional programming language is a functional language that has been extended with special annotations that provide an extra degree of control over parallel evaluation. Of most interest are annotations that allow one to express the dynamic mapping of a program onto a known multiprocessor topology. Since it is quite desirable to provide a precise semantics for any programming language, in this paper adenotational semantics is given for a simple para-functional programming language with mapping annotations. A precise meaning is given not only to the normalfunctional behavior of the program (i.e., the answer), but also to theoperational notion of where (i.e., on what processor) expressions are evaluated. The latter semantics is accomplished through an abstract entity called anexecution tree.This research was supported in part by the National Science Foundation under Grants DCR-8403304 and DCR-8451415, and the Department of Energy under Grant DE-FG02-86ER25012.     

Eiffel语言的语义

本文采用类ＶＤＭ的指称语义技术为Ｅｉｆｆｅｌ（１９８８）语言建立了形式语义模型．该模型首先为Ｅｉｆｆｅｌ语言定义了对象模型和两个语义环境（动态和静态环境）,然后讨论Ｅｉｆｆｅｌ例程的语义．为了描述Ｅｉｆｆｅｌ的意外处理,我们采用了ＶＤＭ的“出口”机制．     

自然语言句子抽象语义表示AMR研究综述

句子的语义处理是自然语言处理的重要难题与挑战。抽象语义表示(Abstract meaning representation, AMR)是近几年国际上新兴的句子级语义表示方法,突破了传统的句法树结构的限制,将一个句子语义抽象为一个单根有向无环图,很好地解决了论元共享问题,成为语言资源建设和句子语义解析的研究热点。本文从AMR概念与规范、解析算法和应用等方面对AMR相关研究进行系统的梳理,特别对AMR的各种解析算法进行了比较深入的分析和比较,指出了现有算法存在的问题和不足,同时介绍了中文AMR的开发进展,最后展望了AMR未来的研究方向。     

Denotational semantics of a synchronous VHDL subset

A denotational definition for a single clock synchronous subset of VHDL is proposed. The different domains for variables and signals, the elaboration of static environments, and the formulation of a simulation algorithm for the sub-language characterize this definition, and distinguish it from more traditional denotational semantics of programming languages.     

分布式系统下的资源安全性计算

主要从理论上研究保证分布式计算中资源安全性的方法。抽象地将每个进程表示为一个数据对,由给定资源和分配给分布式计算的资源两部分组成。在此基础之上,定义了一系列基于指称语义的数学计算,进而将资源安全性问题抽象为数学上的运算。     

Executable structural operational semantics in Maude

This paper describes in detail how to bridge the gap between theory and practice when implementing in Maude structural operational semantics described in rewriting logic, where transitions become rewrites and inference rules become conditional rewrite rules with rewrites in the conditions, as made possible by the new features in Maude 2. We validate this technique using it in several case studies: a functional language Fpl (evaluation and computation semantics), an imperative language WhileL (evaluation and computation semantics), Kahn’s functional language Mini-ML (evaluation or natural semantics), Milner’s CCS (with strong and weak transitions), and Full LOTOS (including ACT ONE data type specifications). In addition, on top of CCS we develop an implementation of the Hennessy–Milner modal logic for describing local capabilities of processes, and for LOTOS we build an entire tool where Full LOTOS specifications can be entered and executed (without user knowledge of the underlying implementation of the semantics). We also compare this method based on transitions as rewrites with another one based on transitions as judgements.