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Graph Reduction Machine
A graph reduction machine is a special-purpose computer built to perform combinator calculations by graph reduction. Examples include the SKIM ("S-K-I machine") computer, built at the University of Cambridge Computer Laboratory, and the multiprocessor GRIP ("Graph Reduction In Parallel") computer, built at University College London. See also *SECD machine The SECD machine is a highly influential (''see: '') virtual machine and abstract machine intended as a target for functional programming language compilers. The letters stand for Stack, Environment, Control, Dump—the internal registers of the mac ... References *T. J. W. Clarke, P. Gladstone, C. MacLean, A. C. Norman: ''SKIM — The S, K, I Reduction Machine''. LISP Conference, 1980: 128–135 External linksReduction Machines Parallel Functional Programming: An Introduction, Kevin Hammond Applicative computing systems Functional programming University of Cambridge Computer Laboratory {{Compu-hardware-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer
A computer is a machine that can be programmed to Execution (computing), carry out sequences of arithmetic or logical operations (computation) automatically. Modern digital electronic computers can perform generic sets of operations known as Computer program, programs. These programs enable computers to perform a wide range of tasks. A computer system is a nominally complete computer that includes the Computer hardware, hardware, operating system (main software), and peripheral equipment needed and used for full operation. This term may also refer to a group of computers that are linked and function together, such as a computer network or computer cluster. A broad range of Programmable logic controller, industrial and Consumer electronics, consumer products use computers as control systems. Simple special-purpose devices like microwave ovens and remote controls are included, as are factory devices like industrial robots and computer-aided design, as well as general-purpose devi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Combinator
Combinatory logic is a notation to eliminate the need for quantified variables in mathematical logic. It was introduced by Moses Schönfinkel and Haskell Curry, and has more recently been used in computer science as a theoretical model of computation and also as a basis for the design of functional programming languages. It is based on combinators, which were introduced by Schönfinkel in 1920 with the idea of providing an analogous way to build up functions—and to remove any mention of variables—particularly in predicate logic. A combinator is a higher-order function that uses only function application and earlier defined combinators to define a result from its arguments. In mathematics Combinatory logic was originally intended as a 'pre-logic' that would clarify the role of quantified variables in logic, essentially by eliminating them. Another way of eliminating quantified variables is Quine's predicate functor logic. While the expressive power of combinatory logic t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graph Reduction
In computer science, graph reduction implements an efficient version of non-strict evaluation, an evaluation strategy where the arguments to a function are not immediately evaluated. This form of non-strict evaluation is also known as lazy evaluation and used in functional programming languages. The technique was first developed by Chris Wadsworth in 1971. Motivation A simple example of evaluating an arithmetic expression follows: : \begin & & &((2+2)+(2+2))+(3+3) \\ & &=&((2+2)+(2+2))+ 6 \\ & &=&((2+2)+ 4)+6 \\ & &=&(4+4)+6 \\ & &=&8+6 \\ & &=&14 \end The above reduction sequence employs a strategy known as outermost tree reduction. The same expression can be evaluated using innermost tree reduction, yielding the reduction sequence: : \begin & & &((2+2)+(2+2))+(3+3) \\ & &= &((2+2)+4)+(3+3) \\ & &= &(4+4)+(3+3) \\ & &= &(4+4)+6 \\ & &= &8+6 \\ & &= &14 \end Notice that the reduction order is made explicit by the addition of parentheses. This expression could ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Cambridge Computer Laboratory
The Department of Computer Science and Technology, formerly the Computer Laboratory, is the computer science department of the University of Cambridge. it employed 35 academic staff, 25 support staff, 35 affiliated research staff, and about 155 research students. The current Head of Department is Professor Ann Copestake. History The Department was founded as the Mathematical Laboratory under the leadership of John Lennard-Jones on 14 May 1937, though it did not get properly established until after World War II. The new laboratory was housed in the North Wing of the former Anatomy School, on the New Museums Site. Upon its foundation, it was intended "to provide a computing service for general use, and to be a centre for the development of computational techniques in the University". The Cambridge Diploma in Computer Science was the world's first postgraduate taught course in computing, starting in 1953. In October 1946, work began under Maurice Wilkes on EDSAC (''Electronic D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University College London
, mottoeng = Let all come who by merit deserve the most reward , established = , type = Public research university , endowment = £143 million (2020) , budget = £1.544 billion (2019/20) , chancellor = Anne, Princess Royal(as Chancellor of the University of London) , provost = Michael Spence , head_label = Chair of the council , head = Victor L. L. Chu , free_label = Visitor , free = Sir Geoffrey Vos , academic_staff = 9,100 (2020/21) , administrative_staff = 5,855 (2020/21) , students = () , undergrad = () , postgrad = () , coordinates = , campus = Urban , city = London, England , affiliations = , colours = Purple and blue celeste , nickname ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SECD Machine
The SECD machine is a highly influential (''see: '') virtual machine and abstract machine intended as a target for functional programming language compilers. The letters stand for Stack, Environment, Control, Dump—the internal registers of the machine. The registers Stack, Control, and Dump point to (some realisations of) stacks, and Environment points to (some realisation of) an associative array. The machine was the first to be specifically designed to evaluate lambda calculus expressions. It was originally described by Peter J. Landin in "The Mechanical Evaluation of Expressions" in 1964. The description published by Landin was fairly abstract, and left many implementation choices open (like an operational semantics). Lispkit Lisp was an influential compiler based on the SECD machine, and the SECD machine has been used as the target for other systems such as Lisp/370. In 1989 researchers at the University of Calgary worked on a hardware implementation of the machine.A pape ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Applicative Computing Systems
Applicative computing systems, or ACS are the systems of object calculi founded on combinatory logic and lambda calculus. The only essential notion which is under consideration in these systems is the representation of object. In combinatory logic the only metaoperator is application in a sense of applying one object to other. In lambda calculus two metaoperators are used: application – the same as in combinatory logic, and functional abstraction which binds the only variable in one object. Features The objects generated in these systems are the functional entities with the following features: # the number of argument places, or object arity is not fixed but is enabling step by step in interoperations with other objects; # in a process of generating the compound object one of its counterparts—function—is applied to other one—argument—but in other contexts they can change their roles, i.e. functions and arguments are considered on the equal rights; # the self-app ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Functional Programming
In computer science, functional programming is a programming paradigm where programs are constructed by Function application, applying and Function composition (computer science), composing Function (computer science), functions. It is a declarative programming paradigm in which function definitions are Tree (data structure), trees of Expression (computer science), expressions that map Value (computer science), values to other values, rather than a sequence of Imperative programming, imperative Statement (computer science), statements which update the State (computer science), running state of the program. In functional programming, functions are treated as first-class citizens, meaning that they can be bound to names (including local Identifier (computer languages), identifiers), passed as Parameter (computer programming), arguments, and Return value, returned from other functions, just as any other data type can. This allows programs to be written in a Declarative programming, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
