Bitcoin is both a cryptocurrency and an electronic payment system,3 invented by an unidentified programmer, or group of programmers, under the name of Satoshi Nakamoto. Bitcoin was introduced on 31 October 2008 to a mailing list. The identity of Nakamoto remains unknown, though many have claimed to know it, the system is peer-to-peer, and transactions take place between users directly, without an intermediary. These transactions are verified by network nodes and recorded in a public distributed ledger called the blockchain, since the system works without a central repository or single administrator, the U. S. Treasury categorizes bitcoin as a decentralized virtual currency. Bitcoin is often called the first cryptocurrency, although prior systems existed, Bitcoin is the largest of its kind in terms of total market value. Bitcoins are created as a reward in a competition in which users offer their computing power to verify and this activity is referred to as mining and successful miners are rewarded with transaction fees and newly created bitcoins.
Besides being obtained by mining, bitcoins can be exchanged for other currencies, when sending bitcoins, users can pay an optional transaction fee to the miners. This may expedite the transaction being confirmed, as of February 2015, over 100,000 merchants and vendors accept bitcoin as payment. Instead of a 2–3% fee typically imposed by credit card processors, despite the fourfold increase in the number of merchants accepting bitcoin in 2014, the cryptocurrency did not have much momentum in retail transactions. The European Banking Authority and other sources have warned that bitcoin users are not protected by refund rights or chargebacks, the use of bitcoin by criminals has attracted the attention of financial regulators, legislative bodies, law enforcement, and media. Criminal activities are focused on darknet markets and theft, though officials in countries such as the United States recognize that bitcoin can provide legitimate financial services. The word bitcoin occurred in the paper that defined bitcoin published in 2008.
It is a compound of the bit and coin. The white paper uses the shorter coin. There is no convention for bitcoin capitalization. Some sources use Bitcoin, capitalized, to refer to the technology and network and bitcoin, the Wall Street Journal, The Chronicle of Higher Education, and the Oxford English Dictionary advocate use of lowercase bitcoin in all cases, which this article follows. The blockchain is a ledger that records bitcoin transactions. A novel solution accomplishes this without any trusted central authority, maintenance of the blockchain is performed by a network of communicating nodes running bitcoin software, transactions of the form payer X sends Y bitcoins to payee Z are broadcast to this network using readily available software applications
Inverted question and exclamation marks
They can be combined in several ways to express the combination of a question and surprise or disbelief. The initial marks are normally mirrored at the end of the sentence or clause by the common used in most other languages. Unlike the ending marks, which are printed along the baseline of a sentence, inverted marks were originally recommended by the Real Academia Española in 1754, and adopted gradually over the next century. On computers, inverted marks are supported by various standards, including ISO-8859-1, Unicode and they can be entered directly on keyboards designed for Spanish-speaking countries, or via alternative methods on other keyboards. The inverted question mark is a punctuation mark written before the first letter of a sentence or clause to indicate that a question follows. It is a form of the standard symbol. Recognized by speakers of languages written with the Latin alphabet, in most languages, a single question mark is used, and only at the end of an interrogative sentence, How old are you.
This was once true of the Spanish language. g, the Real Academia ordered the same inverted-symbol system for statements of exclamation, using the symbols ¡ and. This helps to recognize questions and exclamations in long sentences, are translated respectively as ¿Te gusta el verano. and Te gusta el verano. These new rules were adopted, there exist nineteenth-century books in which the writer does not use either opening symbol. Some writers omit the inverted question mark in the case of a short unambiguous question such as and this is the criterion in Catalan. Certain Catalan-language authorities, such as Joan Solà, insist that both the opening and closing question marks be used for clarity, some Spanish-language writers, among them Nobel laureate Pablo Neruda, refuse to use the inverted question mark. It is common in Internet chat rooms and instant messaging now to use only the single, as an ending symbol for a question, since it saves typing time—using most keyboard layouts, it is easier to type the closing symbol than the opening, inverted symbol.
Multiple closing symbols are used for emphasis, Por qué dices eso. instead of the standard ¿Por qué dices eso, some may use the ending symbol for both beginning and ending, giving. Por qué dices eso. Unspoken uncertainty is expressed in writing with ¿. and surprise with ¡, in 1668, John Wilkins proposed using the inverted exclamation mark ¡ as a symbol at the end of a sentence to denote irony. He was one of many, including Desiderius Erasmus, who there was a need for such a punctuation mark. In both cases, the i in the named entity reference is an initialism for inverted. ¿ is available in all keyboard layouts for Spanish-speaking countries, Windows users with a US keyboard layout are able to switch to the US-International layout. Among other changes, this converts the Alt key to the right of the bar into the Alt-Gr key
An asterisk is a typographical symbol or glyph. It is so called because it resembles a conventional image of a star, computer scientists and mathematicians often vocalize it as star. In English, an asterisk is usually five-pointed in sans-serif typefaces, six-pointed in serif typefaces and it can be used as censorship. It is used on the Internet to correct ones spelling, the asterisk is derived from the need of the printers of family trees in feudal times for a symbol to indicate date of birth. The original shape was seven-armed, each arm like a shooting from the center. In computer science, the asterisk is used as a wildcard character, or to denote pointers, repetition. Origin Adamantius is known to have used the asteriskos to mark missing Hebrew lines from his Hexapla. The asterisk evolved in shape over time, but its meaning as a used to correct defects remained. In the Middle Ages, the asterisk was used to emphasize a part of text. However, an asterisk was not always used, one hypothesis to the origin of the asterisk is that it stems from the five thousand year old Sumerian character dingir,
The ampersand is the logogram &, representing the conjunction word and. It originated as a ligature of the et, Latin for. The word ampersand is a corruption of the phrase and per se &, meaning and intrinsically the word, when reciting the alphabet in English-speaking schools, any letter that could be used as a word in itself was repeated with the Latin expression per se. This habit was useful in spelling where a word or syllable was repeated after spelling, e. g. d, o, g—dog would be clear but simply saying a—a would be confusing without the clarifying per se added. It was common practice to add the & sign at the end of the alphabet as if it were the 27th letter, pronounced as the Latin et or in English as and. As a result, the recitation of the alphabet would end in X, Y, Z and this last phrase was routinely slurred to ampersand and the term had entered common English usage by 1837. Through popular etymology, it has been claimed that André-Marie Ampère used the symbol in his widely read publications.
The ampersand can be traced back to the 1st century A. D. during the following development of the Latin script that led up to the Carolingian minuscule the use of ligatures in general diminished. The et-ligature, continued to be used and gradually became more stylized, the modern italic type ampersand is a kind of et ligature that goes back to the cursive scripts developed during the Renaissance. After the advent of printing in Europe in 1455, printers made extensive use of both the italic and Roman ampersands, since the ampersands roots go back to Roman times, many languages that use a variation of the Latin alphabet make use of it. The ampersand often appeared as a letter at the end of the Latin alphabet, similarly, & was regarded as the 27th letter of the English alphabet, as used by children. An example may be seen in M. B, moores 1863 book The Dixie Primer, for the Little Folks. The popular Apple Pie ABC finishes with the lines X, Y, Z, the ampersand should not be confused with the Tironian et, which is a symbol similar to the numeral 7.
Both symbols have their roots in the antiquity, and both signs were used up through the Middle Ages as a representation for the Latin word et. However, while the ampersand was in origin a common ligature in the everyday script, the Tironian et is found in old Irish language script, a Latin-based script generally only used for decorative purposes today, where it signifies agus in Irish. This symbol may have entered the language by way of monastic influence in the time of the early Christian church in Ireland. In everyday handwriting, the ampersand is sometimes simplified in design as a large lowercase epsilon or a backwards numeral 3 superimposed by a vertical line. The ampersand is shown as a backwards 3 with a vertical line above and below it or a dot above
It appears in a variety of uses in some modern languages and is present in Unicode as code point U+00B7 · Middle dot. The multiplication dot, whose glyphs are similar or identical to the interpunct, is a multiplication sign optionally used instead of the styled ×, the same sign is used in vector multiplication to discriminate between the scalar product and the vector cross product or exterior product. As a multiplication operator, it is encountered in symbols for compound units such as the newton-meter. The multiplication dot is a separate Unicode character, but is often replaced by the interpunct or bullet. Various dictionaries use the interpunct to indicate syllabification within a word with multiple syllables, there is a separate Unicode character, U+2027 ‧ hyphenation point. In British typography, the dot is an interpunct used as the formal decimal point. Its use is advocated by laws and by academic circles such as the Cambridge University History Faculty Style Guide and is mandated by some UK-based academic journals such as The Lancet, the space dot may still be used frequently in handwriting, however.
In the Shavian alphabet, interpuncts replace capitalization as the marker of proper nouns, the dot is placed at the beginning of a word. The flown dot is used in Catalan between two Ls in cases where each belongs to a syllable, for example cel·la, cell. This distinguishes such geminate Ls, which are pronounced, from double L, in situations where the flown dot is unavailable, periods or hyphens are frequently used as substitutes, but this is tolerated rather than encouraged. Historically, medieval Catalan used the symbol ⟨·⟩ as a marker for certain elisions, much like the modern apostrophe, there is no separate keyboard layout for Catalan, the flown dot can be typed using Shift-3 in the Spanish layout. It appears in Unicode as the letters ⟨Ŀ⟩ and ⟨ŀ⟩, the larger bullet may be seen but is discouraged on aesthetic grounds. The preferred Unicode representation is ⟨l·⟩, the partition sign is used in Chinese to mark divisions in transliterated foreign words, particularly names. This is properly a full-width punctuation mark, although sometimes narrower forms are substituted for aesthetic reasons, in particular, the regular interpunct is more commonly used as a computer input, although Chinese-language fonts typically render this as full width.
When the Chinese text is romanized, the sign is simply replaced by a standard space or other appropriate punctuation. Thus, William Shakespeare is signified as 威廉·莎士比亞 or 威廉·莎士比亚, George W. Bush as 喬治·W·布殊 or 乔治·W·布什, titles and other translated words are not similarly marked, Genghis Khan and Elizabeth II are simply 成吉思汗 and 伊利沙伯二世 or 伊麗莎白二世 without a partition sign. The partition sign is used to separate book and chapter titles when they are mentioned consecutively, book first. It appears in Swedish sinologist Bernhard Karlgrens works, where an interpunct is used to represent the stop in his reconstruction of medieval Chinese
The equals sign or equality sign is a mathematical symbol used to indicate equality. It was invented in 1557 by Robert Recorde, in an equation, the equals sign is placed between two expressions that have the same value. In Unicode and ASCII, it is U+003D = equals sign, the etymology of the word equal is from the Latin word æqualis as meaning uniform, identical, or equal, from aequus. The = symbol that is now accepted in mathematics for equality was first recorded by Welsh mathematician Robert Recorde in The Whetstone of Witte. The original form of the symbol was much wider than the present form.2. Thynges, can be moare equalle. … to avoid the repetition of these words, is equal to, I will set a pair of parallels, or Gemowe lines, of one length. According to Scotlands University of St Andrews History of Mathematics website, the symbol || was used by some and æ, from the Latin word aequalis meaning equal, was widely used into the 1700s. In mathematics, the sign can be used as a simple statement of fact in a specific case, or to create definitions, conditional statements.
The first important computer programming language to use the sign was the original version of Fortran, FORTRAN I, designed in 1954. In Fortran, = serves as an assignment operator, X =2 sets the value of X to 2. This somewhat resembles the use of = in a definition, but with different semantics. For example, the assignment X = X +2 increases the value of X by 2, a rival programming-language usage was pioneered by the original version of ALGOL, which was designed in 1958 and implemented in 1960. ALGOL included a relational operator that tested for equality, allowing constructions like if x =2 with essentially the same meaning of = as the usage in mathematics. The equals sign was reserved for this usage, both usages have remained common in different programming languages into the early 21st century. As well as Fortran, = is used for assignment in such languages as C, Python, but = is used for equality and not assignment in the Pascal family, Eiffel, APL, and other languages. A few languages, such as BASIC and PL/I, have used the sign to mean both assignment and equality, distinguished by context.
However, in most languages where = has one of these meanings, a different character or, more often, following ALGOL, most languages that use = for equality use, = for assignment, although APL, with its special character set, uses a left-pointing arrow. Fortran did not have an equality operator until FORTRAN IV was released in 1962, the language B introduced the use of == with this meaning, which has been copied by its descendant C and most languages where = means assignment
The pair consists of an opening quotation mark and a closing quotation mark, which may or may not be the same character. Quotation marks have a variety of forms in different languages and in different media, the double quotation mark is older than the single. By the middle sixteenth century, printers had developed a form of this notation. In most other languages, including English, the marginal marks dropped out of use in the last years of the eighteenth century, the usage of a pair of marks and opening, at the level of lower case letters was generalized. By the nineteenth century, the design and usage began to be specific within each region, in Western Europe the usage became to use the quotation marks in pairs but “pointing” outside. In Britain those marks were elevated to the height of the top of capital letters. In France, by the end of the century those marks were modified to a more angular shape. Some authors claim that the reason for this was a one, in order to get a character that was clearly distinguishable from the apostrophes, the commas.
Other authors claim that the reason for this was an aesthetical one, while other languages do not insert a space between the quotation marks and the word, the French usage does insert them, even if it is a narrow space. The curved quotation marks usage was exported to some non-Latin scripts, the angular quotation marks usage was exported to some non-Latin scripts, like Greek, Cyrillic and Ethiopic. The Far East angle brackets quotation marks are a development of the angular quotation marks. In Central Europe, the practice was to use the marks in pairs. The German tradition preferred the curved quotation marks, the first one at the level of the commas, these marks still “pointed” inside but could be angular and in-line with lower case letters. Some neighboring regions adopted the German tradition but some adopted the second mark as “pointing” to the right. In Sweden, both marks “pointed” to the right but both were at the top level, neither at the bottom, in Eastern Europe there was a hesitation between the French tradition and the German tradition.
The single quotation mark emerged around 1800 as a means of indicating a level of quotation. One could expect that the logic would be the corresponding single mark everywhere, British English tends to reverse the usage — single quotation marks are primary, and double quotation marks are secondary —this distinction, dating back to around the 1960s. In some languages using the quotation marks, the usage of single ones became obsolete, being replaced by double curved ones
In many national currencies, the cent, commonly represented by the cent sign is a monetary unit that equals 1⁄100 of the basic monetary unit. Etymologically, the word cent derives from the Latin word centum meaning hundred, cent refers to a coin worth one cent. In the United States and Canada, the 1¢ coin is known by the nickname penny, alluding to the British coin. In Ireland the 1c coin is sometimes known as a penny in reference to the Irish penny. A cent is commonly represented by the cent sign, a letter c crossed by a diagonal stroke or a vertical line, ¢, or a simple c. Cent amounts from 1 cent to 99 cents can be represented as one or two digits followed by the abbreviation, or as a subdivision of the base unit. The cent sign has not survived the changeover from typewriters to computer keyboards, for the US International keyboard, <Right Alt> <Shift> c. On Macintosh systems, hold ⌥ Option and press 4 on the number row, on Unix/Linux systems with a compose key, Compose+|+C is a typical sequence.
The cent sign has Unicode code point, U+00A2 ¢ cent sign, usage of the cent symbol varies from one currency to another. In the United States and Mexico, the usage ¢ is more common, while in Australia, New Zealand and the eurozone, in South Africa and Ireland, only the c is used. When written in English, the cent sign follows the amount, in contrast with a currency symbol. For example, 2¢ and $0.02, or 2c, greek coins have ΛΕΠΤΟ on the obverse of the one-cent coin and ΛΕΠΤΑ on the obverse of the others. Actual usage varies depending on language, South Korean Won no fractional denomination in circulation, formerly divided into 100 jeon
The austral was the currency of Argentina between June 15,1985 and December 31,1991. It was subdivided into 100 centavos, the symbol was an uppercase A with an extra horizontal line, codepoint U+20B3 Austral sign ₳. This symbol appeared on all issued in this currency, to distinguish them from earlier currencies. The ISO4217 code is ARA, finance Minister Juan Vital Sourrouille devised the Austral plan. The austral replaced the peso argentino at a rate of 1 austral =1000 pesos argentinos and it was itself replaced by the peso at a rate of 1 peso =10,000 australes. In 1985, coins were introduced for ½,1,5,10 and 50 centavos. The ½ centavo was only issued in 1985, whilst production of the 1 centavo ceased in 1987,5 centavo ceased in 1988, and that of the other centavo coins ended in 1989. In 1989,1,5 and 10 austral coins were issued, followed in 1990 and 1991 by 100,500 and 1,000 austral denominations. In 1985, provisional issues were made consisting of 1000,5000 and 10,000 peso argentino notes over stamped with the values 1,5 and 10 australes.
Between 1985 and 1991, the notes were issued by the Banco Central, All banknotes except the provisional types show on the back an image of Liberty with a torch. The provisional banknotes were produced from modified peso ley plates, on the obverses, the word PESOS were erased, whilst the reverse designs substituted the picture with the denomination written in words without spaces in several rows. The denomination was shown on both faces in the form A10 MIL, A50 MIL and A500 MIL, official website of the Banco Central de la República Argentina Argentine Notes
The dash is a punctuation mark that is similar to a hyphen or minus sign, but differs from both of these symbols primarily in length and function. Glitter, felt and buttons—his kitchen looked as if a clown had exploded, a flock of sparrows—some of them juveniles—alighted and sang. The en dash indicates spans or differentiation, where it may be considered to replace and or to, The French and Indian War was fought in western Pennsylvania and along the present US–Canada border. —Mahatma Gandhi There are several forms of dash, of which the most common are, Less common are the dash and three-em dash. The figure dash is so named because it is the width as a digit. This is true of most fonts, not only monospaced fonts, the figure dash is used when a dash must be used within numbers. It does not indicate a range, for which the en dash is used, nor does it function as the minus sign, the figure dash is often unavailable, in this case, one may use a hyphen-minus instead. In Unicode, the dash is U+2012.
HTML authors must use the numeric forms ‒, or ‒, to type it unless the file is in Unicode, there is no equivalent character entity. In TeX, the fonts have no figure dash, however. In XeLaTeX, one could use \char2012, the en dash, n dash, n-rule, or nut is traditionally half the width of an em dash. In modern fonts, the length of the en dash is not standardized, the widths of en and em dashes have been specified as being equal to those of the upper-case letters N and M respectively, and at other times to the widths of the lower-case letters. This may include such as those between dates, times, or numbers. Various style guides restrict this range indication style to only parenthetical or tabular matter, for example, APA style uses an en dash in ranges, but AMA style uses a hyphen. Various style guides recommend that when a number range might be misconstrued as subtraction, the word to should be used instead of an en dash. For example, a voltage of 50 V to 100 V is preferable to using a voltage of 50–100 V.
Relatedly, in ranges that include negative numbers, to is used to avoid ambiguity or awkwardness. It is considered poor style to use the en dash in place of the words to or and in phrases that follow the forms from X to Y, the en dash can be used to contrast values, or illustrate a relationship between two things. Examples of this include, Australia beat American Samoa 31–0
The at sign, @, normally read aloud as at, commonly called the at symbol or commercial at, was originally an accounting and commercial invoice abbreviation meaning at a rate of. In contemporary use, the at sign is most commonly used in email addresses and it is now universally included on computer keyboards. The mark is encoded as U+0040 @ Commercial AT, the earliest yet discovered reference to the @ symbol is a religious one, it features in a Bulgarian translation of a Greek chronicle written by Constantinos Manasses in 1345. Held today in the Vatican Apostolic Library, it features the @ symbol in place of the letter alpha A in the word Amen. Why it was used in context is still a mystery. In terms of the character of the at sign, there are several theories pending verification. One theory is that the developed as a mercantile shorthand symbol of each at. For example, the cost of 12 apples @ $1 would be $12, whereas the cost of 12 apples at $1 would be $1, another theory is that medieval monks abbreviated the Latin word ad next to a numeral.
One reason for the abbreviation saving space and ink, a theory concerning this graphic puts forward the idea that the form derives from the Latin word ad, using the older form of lower case d, ∂, which persists as the partial derivative symbol. It has been theorized that it was originally an abbreviation of the Greek preposition ανά, meaning at the rate of or per. It is used like this in Modern French, Swedish or Czech, in view, the at-symbol is a stylised form of à. The compromise between @ and à in French handwriting is found in street market signs, an Italian academic claims to have traced the @ symbol to the 16th century, in a mercantile document sent by Florentine Francesco Lapi from Seville to Rome on May 4,1536. The document is about commerce with Pizarro, in particular the price of an @ of wine in Peru, in Italian, the symbol was interpreted to mean amphora. Currently, the word means both the at-symbol and a unit of weight. Until now the first historical document containing a symbol resembling a @ as a one is the Spanish Taula de Ariza.
Even though the oldest fully developed modern @ sign is the one found on the above-mentioned Florentine letter, in contemporary English usage, @ is a commercial symbol, called at site or at rate meaning at and at the rate of. It has rarely used in financial documents or grocers price tags. Since 23 October 2012, the At-sign is registered as a mark by the German Patent