TP_SDDT的设计与实现

ＴＰ＿ＳＤＤＴ是Ｔｕｒｂｏ ＰＡＳＣＡＬ环境中一个有效的软件工具，凡是与语法有关的软件开发工作，如语法分析，元级操作和部分求值等，均可利用ＴＰ＿ＳＤＤＴ来完成，本文介绍了ＴＰ＿ＳＤＤＴ的设计思想及实现技术。ＴＰ＿ＳＤＤＴ已在微机上实现。     

功能规约自动生成

ＮＤＲＡＳＳ系统是南京大学计算机软件研究所新近研制成的一个由软件需求定义到软件功能规约的转换系统。功能规约自动生成是该系统的主体部分。它涉及状态空间的生成，操作定义的生成和系统总控流程的生成等。本文简要阐述了这些问题，特别讨论了ＮＤＲＡＳＳ系统中控制流图的规范化与结构化分解，全文包括研究动因、ＮＤＲＡＳＳ系统、功能规约自动生成架构、控制流图的规范化和结构化、代码生成、示例以及结语七个部分。     

基于类型理论的面向对象程序设计

构造性类型理论可作为程序开发的理论基础，其中类型作为程序规约，证明过程作为程序开发过程，从证明抽取满足程序规约的程序．本文提出了一种构造性类型理论ＴＴＯＯＰ，引入了类规约类型和类类型的概念．类是类规约类型的元素，它又是一种类型，类的元素为对象．通过证明类规约可构造类，由此构造面向对象软件．     

TPS系统在焙烧炉中的应用

本文简要介绍山西铝厂焙烧炉ＴＰＳ系统的结构和功能，主要介绍ＴＰＳ系统在流态闪速焙烧炉中的应用，提高了我厂ＤＣＳ的应用水平，解决了Ｙ２Ｋ问题。     

小议DTP市场的误区

小议ＤＴＰ市场的误区文：远征对大多数印刷企业和传统照相制版厂来说，目前日新月异的数字化印前技术就像是一个迷宫，科技进步和市场需求已使这类企业身不由己地置身于这个迷宫之中，随之产生一联串的问题：自己要不要上一套ＤＴＰＳＹＳ？采用什么样的步骤上系统？……...     

DFA模型及其语言的结构化代数规约

本文首先阐述了利用ＤＦＡ模型技术进行状态转换系统描述存在的主要问题,提出了利用代数规约技术解决这些问题的可行性,然后介绍了新一代具有松散语义的代数规约语言ＳＰＥＣＴＲＵＭ及其主要规约操作符的语法和语义,并根据ＤＦＡ模型及其语言的数学定义,给出了它们的结构化代数规约,为基于ＤＦＡ模型的状态转换系统的形式化设计和开发奠定了基础。     

方便的文件传输软件——Cute FTP

方便的文件传输软件———ＣｕｔｅＦＴＰ文：谢勇ＦＴＰ是Ｉｎｔｅｒｎｅｔ上传输文件的主要方法，而Ｗｉｎｄｏｗｓ９５中内置的ＦＴＰ程序，类似ＤＯＳ的字符界面，且命令繁多复杂，不易掌握。只因它是Ｗｉｎｄｏｗｓ９５自带的软件，比较容易获得。一旦通过它进入ＦＴ...     

一种程序综合方法

通过证明程序规约的方法可构造相应程序，但对“难题”和无证明的规约，无法使用这种方法构造程序，另一方面，如果可构造程序规约的验证程序，则可把这种程序看成该仙约的程序。本文讨论了程序规约的验证程序的构造方法，作为研究程序自动佛的一种途径。     

基于类型理论的面向对象多步证明系统

介绍基于扩展构造型演算的交互式多步证明系统。该系统中以函数式语言ML为开发环境，建立了ECC的项、规则证明策略和证明管哩机制的描述，并引入规约类型、类类型、类和对象的表示，为面向对象的程序规约和定理证明系统的结合进行了一些探索。     

基于类型理论的面向对象多步证明系统

介绍基于扩展构造型演算的交互式多步证明系统。该系统中以函数式语言ＭＬ为开发环境，建立了ＥＣＣ的项、规则证明策略和证明管理机制的描述，并引入规约类型、类类型、类和对象的表示，为面向对象的程序规约和定理证明系统的结合进行了一些探索。     

Fundamentals of deductive program synthesis

An informal tutorial for program synthesis is presented, with an emphasis on deductive methods. According to this approach, to construct a program meeting a given specification, the authors prove the existence of an object meeting the specified conditions. The proof is restricted to be sufficiently constructive, in the sense that, in establishing the existence of the desired output, the proof is forced to indicate a computational method for finding it. That method becomes the basis for a program that can be extracted from the proof. The exposition is based on the deductive-tableau system, a theorem-proving framework particularly suitable for program synthesis. The system includes a nonclausal resolution rule, facilities for reasoning about equality, and a well-founded induction rule     

Program Constructionby Verifying Specification

A program construction method based on Gamma language is proposed.The problem to be solved is specified by first-order predicate logic and a semantic verification program is constructed directly from the specification.Ways for improving efficiency of the program are also studied.The method differs from the one proposed by Manna and Waldinger,where a program is extracted from the proof of the existence of an object meeting the given specification.On the other hand,it also differs from the classical one used for deriving Gamma programs of Banatre and Le metayes,which consists in decomposing the specification into an invariant and a termination conditon.     

序列折半划分问题的形式化推导

形式化推导是在程序正确性证明理论下所进行的程序开发,最终得到完全正确的算法程序。针对序列折半划分问题,现有的形式化推导方法将推导与证明交替进行,推导过程繁琐且大多无法直接获得可执行程序。为解决上述问题,提出了一种新的序列折半划分问题的形式化推导方法。该方法基于分划递推的核心思想,应用规约变换技术对问题规约进行变换并严格保证一致性,使得在推导过程中无需交替证明,进而导出递推关系式并得到高可靠性抽象算法程序Apla,最终通过转换工具自动生成可执行程序。实现了从程序规约到具体可执行程序的完整程序求精过程。以2个序列算法为例,验证了该方法的有效性和可行性,对相关问题的形式化推导具有指导意义。     

Verifying programs in the calculus of inductive constructions

This paper deals with a particular approach to the verification of functional programs. A specification of a program can be represented by a logical formula [Con86, NPS90]. In a constructive framework, developing a program then corresponds to proving this formula. Given a specification and a program, we focus on reconstructing a proof of the specification whose algorithmic contents corresponds to the given program. The best we can hope is to generate proof obligations on atomic parts of the program corresponding to logical properties to be verified. First, this paper studies a weak extraction of a program from a proof that keeps track of intermediate specifications. From such a program, we prove the determinism of retrieving proof obligations. Then, heuristic methods are proposed for retrieving the proof from a natural program containing only partial annotations. Finally, the implementation of this method as a tactic of theCoq proof assistant is presented.This research was partly supported by ESPRIT Basic Research Action Types for Proofs and Programs and by Programme de Recherche Coordonnes and CNRS Groupement de Recherche Programmation.     

Deductive synthesis of the unification algorithm

The deductive approach is a formal program construction method in which the derivation of a program from a given specification is regarded as a theorem-proving task. To construct a program whose output satisfies the conditions of the specification, we prove a theorem stating the existence of such an output. The proof is restricted to be sufficiently constructive so that a program computing the desired output can be extracted directly from the proof. The program we obtain is applicative and may consist of several mutually recursive procedures. The proof constitutes a demonstration of the correctness of this program.To exhibit the full power of the deductive approach, we apply it to a nontrivial example—the synthesis of a unification algorithm. Unification is the process of finding a common instance of two expressions. Algorithms to perform unification have been central to many theorem-proving systems and to some programming-language processors.The task of deriving a unification algorithm automatically is beyond the power of existing program synthesis systems. In this paper,we use the deductive approach to derive an algorithm from a simple, high-level specification of the unification task. We will identify some of the capabilities required of a theorem-proving system to perform this derivation automatically.     

Proving programs correct through refinement

Summary Program proving must be made applicable to all stages of program development. In particular, in the design phase, proving could prevent a program development based on erroneous or inconsistent design decisions, with its associated high cost of debugging. Furthermore, the proving activity itself would benefit from an early application in the development cycle of a program, because the proof of a program design seems to be simpler than the proof of the final, perhaps optimized, program. The Fisher-Galler algorithm will be used as an example for demonstrating the proof of a program design. An algebraic specification technique is used for describing the design. Details of the proof will be discussed.     

从构造性证明中提取程序

通常情况下，我们很难确定一段给定的程序是否符合它的规范，程序提取是一种从构造性证明中提取函数式程序的机制，其构造特性很好地保证了生成程序的正确性。这就为我们提供了一种开发正确性软件的方法。本文基于对Coq中程序提取机制的研究，阐述了它的理论基础、实现机制及应用。     

Database Management System Verification with Separation Logics

Programming and Computer Software - Program verification consists in finding a formal proof that the program satisfies a given specification. This specification can be described as assertions about...     

Using Program Transformations to Provide Safety Properties for Real-Time Systems

The process of showing that a program satisfies some particular properties with respect to its specification is called program verification. Axiomatic semantics is a verification method that makes assertions describing properties about the states of a program. There exists a transformation from the assertions of a program's verification proof to executable assertions. The latter may be embedded in the program to make it fault tolerant. An axiomatic proof system for concurrent programs is applied to generate executable assertions in a real time distributed environment. A train set example is used as modelproblem.     

Completely non-clausal theorem proving

The proof procedure we describe operates on quantifier-free formulas of the predicate calculus which are not truth-functionally normalized in any way. The procedure involves a single inference rule called NC-resolution, and is shown to be complete. Completeness is also obtained for a simple restriction on the rule's application.Examples are given using NC-resolution to derive a logic program from its specification, and to ‘execute’ a program specification in its original form.