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Symbols For Zero
The modern numerical digit 0 is usually written as a circle, an ellipse, or a rounded rectangle. Glyphs In most modern typefaces, the height of the 0 character is the same as the other digits. However, in typefaces with text figures, the character is often shorter (x-height). Traditionally, many print typefaces made the capital letter O more rounded than the narrower, elliptical digit 0. Typewriters originally made no distinction in shape between O and 0; some models did not even have a separate key for the digit 0. The distinction came into prominence on modern character displays. The digit 0 with a dot in the centre seems to have originated as an option on IBM 3270 displays. Its appearance has continued with Taligent's command line typeface Andalé Mono. One variation used a short vertical bar instead of the dot. This could be confused with the Greek letter Theta on a badly focused display, but in practice there was no confusion because theta was not (then) a displayable ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
0 (number)
0 (zero) is a number representing an empty quantity. In place-value notation such as the Hindu–Arabic numeral system, 0 also serves as a placeholder numerical digit, which works by multiplying digits to the left of 0 by the radix, usually by 10. As a number, 0 fulfills a central role in mathematics as the additive identity of the integers, real numbers, and other algebraic structures. Common names for the number 0 in English are ''zero'', ''nought'', ''naught'' (), ''nil''. In contexts where at least one adjacent digit distinguishes it from the letter O, the number is sometimes pronounced as ''oh'' or ''o'' (). Informal or slang terms for 0 include ''zilch'' and ''zip''. Historically, ''ought'', ''aught'' (), and ''cipher'', have also been used. Etymology The word ''zero'' came into the English language via French from the Italian , a contraction of the Venetian form of Italian via ''ṣafira'' or ''ṣifr''. In pre-Islamic time the word (Arabic ) had the meanin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Empty Set
In mathematics, the empty set is the unique set having no elements; its size or cardinality (count of elements in a set) is zero. Some axiomatic set theories ensure that the empty set exists by including an axiom of empty set, while in other theories, its existence can be deduced. Many possible properties of sets are vacuously true for the empty set. Any set other than the empty set is called non-empty. In some textbooks and popularizations, the empty set is referred to as the "null set". However, null set is a distinct notion within the context of measure theory, in which it describes a set of measure zero (which is not necessarily empty). The empty set may also be called the void set. Notation Common notations for the empty set include "", "\emptyset", and "∅". The latter two symbols were introduced by the Bourbaki group (specifically André Weil) in 1939, inspired by the letter Ø in the Danish and Norwegian alphabets. In the past, "0" was occasionally used as a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Southwest Airlines
Southwest Airlines Co., typically referred to as Southwest, is one of the major airlines of the United States and the world's largest low-cost carrier. It is headquartered in Dallas, Texas, and has scheduled service to 121 destinations in the United States and 10 additional countries. , Southwest carried more domestic passengers than any other United States airline. The airline was established on March 15, 1967, by Herb Kelleher and Rollin King as Air Southwest Co. and adopted its current name, Southwest Airlines Co., in 1971, when it began operating as an intrastate airline wholly within the state of Texas, first flying between Dallas, Houston, and San Antonio. It began regional interstate service in 1979, expanding nationwide in the following decades. Southwest currently serves airports in 42 states and multiple Central American destinations. Southwest's business model is distinct from other US airlines as it uses a rolling hub and point-to-point network and allows free che ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FE-Schrift
The or ('forgery-impeding typeface') is a sans serif typeface introduced for use on licence plates. Its monospaced letters and numbers are slightly disproportionate to prevent easy modification and to improve machine readability. It has been developed in Germany where it has been mandatory since November 2000. The abbreviation "FE" is derived from the compound German adjective combining the noun " ('falsification') and the verb ('to hinder'). means 'font' in German (cognate with the English word ''script''). Other countries have later introduced the same or a derived typeface for license plates taking advantage of the proven design for the . Development The motivation for the creation of the typeface arose in the late 1970s in the light of Red Army Faction terrorism when it was discovered that with the then-standard font for vehicle registration plates—the DIN 1451 font—it was particularly easy to modify letters by applying a small amount of black paint or tape. F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vehicle Registration Plates Of Germany
German vehicle registration plates (german: Kraftfahrzeug-Kennzeichen or, more colloquially, ) are alphanumeric plates in a standardized format, issued officially by the district authorities to motorized vehicles of German residents. The legal requirements for these licence plates are laid down in a federal law titled (Ordinance on the admission of vehicles for road traffic), or in the shortened version ''Verordnung über die Zulassung von Fahrzeugen zum Straßenverkehr'' , by Bundesanzeiger Verlag, published: 3 February 2011, accessed: 29 October 2020 which replaced part of an older law named in 2011. The law distinguishes between meaning a specific combination of l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vehicle Registration Plate
A vehicle registration plate, also known as a number plate (British English), license plate (American English), or licence plate ( Canadian English), is a metal or plastic plate attached to a motor vehicle or trailer for official identification purposes. All countries require registration plates for road vehicles such as cars, trucks, and motorcycles. Whether they are required for other vehicles, such as bicycles, boats, or tractors, may vary by jurisdiction. The registration identifier is a numeric or alphanumeric ID that uniquely identifies the vehicle or vehicle owner within the issuing region's vehicle register. In some countries, the identifier is unique within the entire country, while in others it is unique within a state or province. Whether the identifier is associated with a vehicle or a person also varies by issuing agency. There are also electronic license plates. Legal requirements In Europe, most governments require a registration plate to be attached to b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TI-99/4A
The TI-99/4 and TI-99/4A are home computers released by Texas Instruments in 1979 and 1981, respectively. Based on the Texas Instruments TMS9900 microprocessor originally used in minicomputers, the TI-99/4 was the first 16-bit home computer. The associated video display controller provides color graphics and sprite support which were only comparable with those of the Atari 400 and 800 released a month after the TI-99/4. The calculator-style keyboard of the TI-99/4 was cited as a weak point, and TI's reliance on ROM cartridges and their practice of limiting developer information to select third parties resulted in a lack of software for the system. The TI-99/4A was released in June 1981 to address some of these issues with a simplified internal design, full-travel keyboard, improved graphics, and a unique expansion system. At half the price of the original model, sales picked up significantly and TI supported the 4A with peripherals, including a speech synthesizer and a "Per ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Line Printer
A line printer prints one entire line of text before advancing to another line. Most early line printers were impact printers. Line printers are mostly associated with unit record equipment and the early days of digital computing, but the technology is still in use. Print speeds of 600 lines per minute (approximately 10 pages per minute) were achieved in the 1950s, later increasing to as much as 1200 lpm. Line printers print a complete line at a time and have speeds in the range of 150 to 2500 lines per minute. The types of line printers are drum printers, band-printers, and chain printers. Other non-impact technologies have also been used, as thermal line printers were popular in the 1970s and 1980s, and some inkjet and laser printers produce output a line or a page at a time. Designs Many impact printers, such as the daisywheel printer and dot matrix printer, used a print head that printed a character then moved on until an entire line was printed. Line printers we ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algol
ALGOL (; short for "Algorithmic Language") is a family of imperative computer programming languages originally developed in 1958. ALGOL heavily influenced many other languages and was the standard method for algorithm description used by the Association for Computing Machinery (ACM) in textbooks and academic sources for more than thirty years. In the sense that the syntax of most modern languages is "Algol-like", it was arguably more influential than three other high-level programming languages among which it was roughly contemporary: FORTRAN, Lisp, and COBOL. It was designed to avoid some of the perceived problems with FORTRAN and eventually gave rise to many other programming languages, including PL/I, Simula, BCPL, B, Pascal, and C. ALGOL introduced code blocks and the begin...end pairs for delimiting them. It was also the first language implementing nested function definitions with lexical scope. Moreover, it was the first programming language which gave detail ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SHARE (computing)
SHARE Inc. is a volunteer-run user group for IBM mainframe computers that was founded in 1955 by Los Angeles-area users of the IBM 701 computer system. It evolved into a forum for exchanging technical information about programming languages, operating systems, database systems, and user experiences for enterprise users of small, medium, and large-scale IBM computers such as IBM S/360, IBM S/370, zSeries, pSeries, and xSeries. Despite the capitalization of all letters in the name, the official website says "SHARE is not an acronym; it's what we do." Overview A major resource of SHARE from the beginning was the SHARE library. Originally, IBM distributed what software it provided in source form and systems programmers commonly made small local additions or modifications and exchanged them with other users. The SHARE library and the process of distributed development it fostered was one of the major origins of open source software. In 1959 SHARE released the SHARE Operating Syst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
