Source

Source may refer to:

Research

Source (International Information Support Centre)

Source is an international information support centre and digital library, providing links to academic resources and articles related to disability, health and international development.

About

Source provides access to a collection of more than 25,000 published and unpublished resources related to health, disability and international development. This includes books, journals, reports, posters, CD-ROMs, manuals, websites and organisations.

Source was set up as a collaborative venture of Healthlink Worldwide, a non-profit organisation, and the Centre for International Health and Development, an academic institution. Handicap International became a partner shortly after. The information support centre aims to increase access to health and disability related resources, produced for and by people with disabilities in developing countries, in order to promote research and learning among health professionals, students, disabled people’s organisations (DPOs) and NGOs working in international development world-wide.

Source (magazine)

Source magazine is a free bi-monthly magazine published by the John Brown Group on behalf of Greenbee, John Lewis, and Waitrose, all three of which are owned by the John Lewis Partnership, with articles covering interior design, beauty, the arts, travel, finance, and lifestyle.

Conception

Source magazine was launched in Autumn 2006, around the time the John Lewis Partnership launched Greenbee, its new direct services company, providing selected services, from insurance to ticket sales and internet service. Source was thus conceived, as well as being a source of entertainment and information, to introduce customers to the Greenbee services (helping to make it a household name), and to reinforce the relationship between the John Lewis Partnership and its customers. It comes from the same stable as Waitrose Food Illustrated, a magazine published for 10 years.

Target audience

Source is intended to appeal to typical John Lewis and Waitrose customers, that is, predominantly upper middle class and middle class (A, B, and to some extent C1) older people. As such, returning advertisers include Prada, Lancôme, Samsung, AEG, and Panasonic. In order to appeal to younger customers, Source has undergone slight changes to give it a more modern look, including changing the font on the spine from serif to sans-serif, and writing the issue numbers in numeric format rather than text.

Mathematical logic

Mathematical logic is a subfield of mathematics exploring the applications of formal logic to mathematics. It bears close connections to metamathematics, the foundations of mathematics, and theoretical computer science. The unifying themes in mathematical logic include the study of the expressive power of formal systems and the deductive power of formal proof systems.

Mathematical logic is often divided into the fields of set theory, model theory, recursion theory, and proof theory. These areas share basic results on logic, particularly first-order logic, and definability. In computer science (particularly in the ACM Classification) mathematical logic encompasses additional topics not detailed in this article; see Logic in computer science for those.

Since its inception, mathematical logic has both contributed to, and has been motivated by, the study of foundations of mathematics. This study began in the late 19th century with the development of axiomatic frameworks for geometry, arithmetic, and analysis. In the early 20th century it was shaped by David Hilbert's program to prove the consistency of foundational theories. Results of Kurt Gödel, Gerhard Gentzen, and others provided partial resolution to the program, and clarified the issues involved in proving consistency. Work in set theory showed that almost all ordinary mathematics can be formalized in terms of sets, although there are some theorems that cannot be proven in common axiom systems for set theory. Contemporary work in the foundations of mathematics often focuses on establishing which parts of mathematics can be formalized in particular formal systems (as in reverse mathematics) rather than trying to find theories in which all of mathematics can be developed.

Boolean-valued function

A boolean-valued function (sometimes called a predicate or a proposition) is a function of the type f : X → B, where X is an arbitrary set and where B is a boolean domain, i.e. a generic two-element set, (for example B = {0, 1}), whose elements are interpreted as logical values, for example, 0 = false and 1 = true.

In the formal sciences, mathematics, mathematical logic, statistics, and their applied disciplines, a boolean-valued function may also be referred to as a characteristic function, indicator function, predicate, or proposition. In all of these uses it is understood that the various terms refer to a mathematical object and not the corresponding semiotic sign or syntactic expression.

In formal semantic theories of truth, a truth predicate is a predicate on the sentences of a formal language, interpreted for logic, that formalizes the intuitive concept that is normally expressed by saying that a sentence is true. A truth predicate may have additional domains beyond the formal language domain, if that is what is required to determine a final truth value.

Spectravideo

Spectravideo, or SVI, was an American computer company founded in 1981 as "SpectraVision" by Harry Fox. They originally made video games for Atari 2600 and VIC-20. Some of their computers were MSX-compliant or IBM PC compatible. They ceased operations in 1988.

History

SpectraVision was founded in 1981 by Harry Fox and Alex Weiss as a distributor of computer games, contracting external developers to write the software. Their main products were gaming cartridges for the Atari 2600 VCS, Colecovision and Commodore VIC-20. They also made the world's first ergonomic joystick, the Quickshot. In late 1982 the company was renamed to Spectravideo due to a naming conflict with OnCommand's Hotel TV system called SpectraVision.

In the early 1980s, the company developed 11 games for the Atari 2600, including several titles of some rarity: Chase the Chuckwagon, Mangia and Bumper Bash. A few of their titles were only available through the Columbia House music club.

The company's first attempt at a computer was an add-on for the Atari 2600 called the Spectravideo CompuMate, with a membrane keyboard and very simple programmability.