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Formal Methods
In computer science, formal methods are mathematically rigorous techniques for the specification, development, and verification of software and hardware systems. The use of formal methods for software and hardware design is motivated by the expectation that, as in other engineering disciplines, performing appropriate mathematical analysis can contribute to the reliability and robustness of a design. Formal methods employ a variety of theoretical computer science fundamentals, including logic calculi, formal languages, automata theory, control theory, program semantics, type systems, and type theory. Background Semi-Formal Methods are formalisms and languages that are not considered fully “formal”. It defers the task of completing the semantics to a later stage, which is then done either by human interpretation or by interpretation through software like code or test case generators. Taxonomy Formal methods can be used at a number of levels: Level 0: Formal specifi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Computer Science
Computer science is the study of computation, automation, and information. Computer science spans theoretical disciplines (such as algorithms, theory of computation, information theory, and automation) to practical disciplines (including the design and implementation of hardware and software). Computer science is generally considered an area of academic research and distinct from computer programming. Algorithms and data structures are central to computer science. The theory of computation concerns abstract models of computation and general classes of problems that can be solved using them. The fields of cryptography and computer security involve studying the means for secure communication and for preventing security vulnerabilities. Computer graphics and computational geometry address the generation of images. Programming language theory considers different ways to describe computational processes, and database theory concerns the management of repositories ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Safety
Safety is the state of being "safe", the condition of being protected from harm or other danger. Safety can also refer to the control of recognized hazards in order to achieve an acceptable level of risk. Meanings There are two slightly different meanings of ''safety''. For example, ''home safety'' may indicate a building's ability to protect against external harm events (such as weather, home invasion, etc.), or may indicate that its internal installations (such as appliances, stairs, etc.) are safe (not dangerous or harmful) for its inhabitants. Discussions of safety often include mention of related terms. Security is such a term. With time the definitions between these two have often become interchanged, equated, and frequently appear juxtaposed in the same sentence. Readers unfortunately are left to conclude whether they comprise a redundancy. This confuses the uniqueness that should be reserved for each by itself. When seen as unique, as we intend here, each term will ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Jeannette Wing
Jeannette Marie Wing is Avanessians Director of the Data Science Institute at Columbia University, where she is also a professor of computer science. Until June 30, 2017, she was Corporate Vice President of Microsoft Research with oversight of its core research laboratories around the world and Microsoft Research Connections. Prior to 2013, she was the President's Professor of Computer Science at Carnegie Mellon University, Pittsburgh, Pennsylvania, United States. She also served as assistant director for Computer and Information Science and Engineering at the NSF from 2007 to 2010. She was appointed the Columbia University executive vice president for research in 2021. Background Wing earned her S.B. and S.M. in Electrical Engineering and Computer Science at MIT in June 1979. Her advisers were Ronald Rivest and John Reiser. In 1983, she earned her Ph.D. in Computer Science at MIT under John Guttag. She is a fourth-degree black belt in Tang Soo Do. Career and research Wing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Daniel Jackson (computer Scientist)
Daniel Jackson (born 1963) is a professor of Computer Science at the Massachusetts Institute of Technology (MIT). He is the principal designer of the Alloy modelling language, and author of the book ''Software Abstractions: Logic, Language, and Analysis''. Biography Jackson was born in London, England, in 1963. He studied physics at the University of Oxford, receiving an MA in 1984. After completing his MA, Jackson worked for two years as a software engineer at Logica UK Ltd. He then returned to academia to study computer science at MIT, where he received an SM in 1988, and a PhD in 1992. Following the completion of his doctorate Jackson took up a position as an Assistant Professor of Computer Science at Carnegie Mellon University, which he held until 1997. He has been on the faculty of the Department of Electrical Engineering and Computer Science at MIT since 1997. In 2017 he became a Fellow of the Association for Computing Machinery. Jackson is also a photographer, and has ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Logic
Logic is the study of correct reasoning. It includes both formal and informal logic. Formal logic is the science of deductively valid inferences or of logical truths. It is a formal science investigating how conclusions follow from premises in a topic-neutral way. When used as a countable noun, the term "a logic" refers to a logical formal system that articulates a proof system. Formal logic contrasts with informal logic, which is associated with informal fallacies, critical thinking, and argumentation theory. While there is no general agreement on how formal and informal logic are to be distinguished, one prominent approach associates their difference with whether the studied arguments are expressed in formal or informal languages. Logic plays a central role in multiple fields, such as philosophy, mathematics, computer science, and linguistics. Logic studies arguments, which consist of a set of premises together with a conclusion. Premises and conclusions are usual ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Postcondition
In computer programming, a postcondition is a condition or predicate that must always be true just after the execution of some section of code or after an operation in a formal specification. Postconditions are sometimes tested using assertions within the code itself. Often, postconditions are simply included in the documentation of the affected section of code. For example: The result of a factorial is always an integer and greater than or equal to 1. So a program that calculates the factorial of an input number would have postconditions that the result after the calculation be an integer and that it be greater than or equal to 1. Another example: a program that calculates the square root of an input number might have the postconditions that the result be a number and that its square be equal to the input. Postconditions in object-oriented programming In some software design approaches, postconditions, along with preconditions and class invariants, are components of the software ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Precondition
In computer programming, a precondition is a condition or predicate that must always be true just prior to the execution of some section of code or before an operation in a formal specification. If a precondition is violated, the effect of the section of code becomes undefined and thus may or may not carry out its intended work. Security problems can arise due to incorrect preconditions. Often, preconditions are simply included in the documentation of the affected section of code. Preconditions are sometimes tested using guards or assertions within the code itself, and some languages have specific syntactic constructions for doing so. For example: the factorial is only defined for integers greater than or equal to zero. So a program that calculates the factorial of an input number would have preconditions that the number be an integer and that it be greater than or equal to zero. In object-oriented programming Preconditions in object-oriented software development are a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Axiomatic Semantics
Axiomatic semantics is an approach based on mathematical logic for proving the correctness of computer programs. It is closely related to Hoare logic. Axiomatic semantics define the meaning of a command in a program by describing its effect on assertions about the program state. The assertions are logical statements—predicates with variables, where the variables define the state of the program. See also * Algebraic semantics (computer science) — in terms of algebras * Denotational semantics In computer science, denotational semantics (initially known as mathematical semantics or Scott–Strachey semantics) is an approach of formalizing the meanings of programming languages by constructing mathematical objects (called ''denotations'' ... — by translation of the program into another language * Operational semantics — in terms of the state of the computation * Formal semantics of programming languages — overview * Predicate transformer semantics — describes the m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Operational Semantics
Operational semantics is a category of formal programming language semantics in which certain desired properties of a program, such as correctness, safety or security, are verified by constructing proofs from logical statements about its execution and procedures, rather than by attaching mathematical meanings to its terms ( denotational semantics). Operational semantics are classified in two categories: structural operational semantics (or small-step semantics) formally describe how the ''individual steps'' of a computation take place in a computer-based system; by opposition natural semantics (or big-step semantics) describe how the ''overall results'' of the executions are obtained. Other approaches to providing a formal semantics of programming languages include axiomatic semantics and denotational semantics. The operational semantics for a programming language describes how a valid program is interpreted as sequences of computational steps. These sequences then ''are'' t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Domain Theory
Domain theory is a branch of mathematics that studies special kinds of partially ordered sets (posets) commonly called domains. Consequently, domain theory can be considered as a branch of order theory. The field has major applications in computer science, where it is used to specify denotational semantics, especially for functional programming languages. Domain theory formalizes the intuitive ideas of approximation and convergence in a very general way and is closely related to topology. Motivation and intuition The primary motivation for the study of domains, which was initiated by Dana Scott in the late 1960s, was the search for a denotational semantics of the lambda calculus. In this formalism, one considers "functions" specified by certain terms in the language. In a purely syntactic way, one can go from simple functions to functions that take other functions as their input arguments. Using again just the syntactic transformations available in this formalism, one can o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Denotational Semantics
In computer science, denotational semantics (initially known as mathematical semantics or Scott–Strachey semantics) is an approach of formalizing the meanings of programming languages by constructing mathematical objects (called ''denotations'') that describe the meanings of expressions from the languages. Other approaches providing formal semantics of programming languages include axiomatic semantics and operational semantics. Broadly speaking, denotational semantics is concerned with finding mathematical objects called domains that represent what programs do. For example, programs (or program phrases) might be represented by partial functionsDana S. ScottOutline of a mathematical theory of computation Technical Monograph PRG-2, Oxford University Computing Laboratory, Oxford, England, November 1970. Dana Scott and Christopher Strachey. ''Toward a mathematical semantics for computer languages'' Oxford Programming Research Group Technical Monograph. PRG-6. 1971. or by ga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Formal Semantics Of Programming Languages
In programming language theory, semantics is the rigorous mathematical study of the meaning of programming languages. Semantics assigns computational meaning to valid strings in a programming language syntax. Semantics describes the processes a computer follows when executing a program in that specific language. This can be shown by describing the relationship between the input and output of a program, or an explanation of how the program will be executed on a certain platform, hence creating a model of computation. History In 1967, Robert W. Floyd publishes the paper ''Assigning meanings to programs''; his chief aim is "a rigorous standard for proofs about computer programs, including proofs of correctness, equivalence, and termination". Floyd further writes: A semantic definition of a programming language, in our approach, is founded on a syntactic definition. It must specify which of the phrases in a syntactically correct program represent commands, and what conditions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |