The word "obelus" comes from the Greek word for a sharpened stick, spit, or pointed pillar. This is the same root as that of the word "obelisk". The obelus was first used as a symbol for division in 1659, in the algebra book "Teutsche Algebra" by Johann Rahn. Today, the obelus is used occasionally, mostly as a standalone symbol for the division operation itself (as on a calculator), or as an operator in elementary arithmetic. In most cases, division is now represented using other ways, often by a forward slash (/), also known as "solidus".
Vinculum (symbol)
A vinculum is a horizontal line put over a mathematical expression. It shows that it belongs together as a group. ("Vinculum" is Latin for "chain".)
Examples are:
1. groups of digits repeating forever, for example,
2. fractions
3. radicals (in the following example the quantity formula_3 is the radicand, and thus has a vinculum over it):
Colon (punctuation)
The colon (":") is a punctuation mark, visually consisting of two equally sized dots centered on the same vertical (up/down) line.
A colon is a more significant pause than a semi-colon. It is usually used to contrast two parts of a sentence:
revealed: chairs overturned, drawers pulled out and emptied, broken crockery on the floor..."
The colon's first appearance in English text is marked by the "Shorter Oxford English Dictionary" as 1589.
A special double-triangle colon symbol is used in IPA to indicate that the preceding sound is long. Its form is that of two triangles, each a bit larger than a point of a standard colon, pointing toward each other. It is available in Unicode as modifier letter triangular colon, Unicode U+02D0 (). A regular colon is often used as a fallback when this character is not available, or in the practical orthography of some languages (particularly in Mexico), which have a phonemic long/short distinction in vowels.
The colon is also used in mathematics, cartography, model building and other fields to denote a ratio or a scale, as in 3:1 (pronounced "three to one"). A betting odd of the form formula_1 corresponds to the probability formula_2. Unicode provides a distinct ratio character, Unicode U+2236 () for mathematical usage.
In many non-English-speaking countries, the colon is used as a division sign: ""a divided by b"" is written as a : b.
The combination with an equal sign, formula_3, is used for definitions.
In computing, the colon character is represented by ASCII code 58, and is located at Unicode code-point U+003A. The full-width (double-byte) equivalent, ：, is located at Unicode code point U+FF1A.
The colon is quite often used as a special control character in many operating systems commands, URLs, computer programming languages, and in the path representation of several file systems. It is often used as a single post-fix delimiter, signifying the immediate precedence of a token keyword or the transition from one mode of character string interpretation to another related mode. Some applications, such as the widely used MediaWiki, use the colon as both a pre-fix and post-fix delimiter.
For a double-colon, "::" the meaning has included the use of ellipsis, as spanning over omitted text; however, there have been other meanings as well.
On the Internet (online chats, email, message boards, etc.), a colon or multiple colons is sometimes used to denote an action or emote. In this use, it has the inverse function of quotation marks—denoting actions where unmarked text is assumed to be dialog. For example:
Colons may also be used for sounds (as with ":Click:"). One can contrast this use with the use of outer asterisks (for example, *cough* would denote that the speaker is coughing, as opposed to saying the word 'cough').
It also has the widespread usage of representing two vertically aligned eyes in a emoticon, such as :-), :( :P, :D, :3, etc.
Colon (disambiguation)
Colon could mean:
Tomorrow Never Knows
Tomorrow Never Knows is a song from The Beatles's "Revolver" album, from 1966.
John Lennon wrote the song based on his readings of "The Psychedelic Experience", which adapted the "Tibetan Book of the Dead" for use as an LSD "user's manual", intending to give users a kind of religious experience. The song's title came from his bandmate Ringo Starr, who was known for his but insightful comments about life.
Lennon wanted the sound of monks , to complement the Beatles' recording of the song. It was not possible to do this, but Lennon's voice was played through a special speaker (called a Leslie speaker), to give it a sound, like a voice calling from a hilltop. Other sounds on the record came from tape loops, playing over and over, and from a sitar.
The song has also been recorded by other artists. A dance cover version appeared in the 1990s.
Gone with the Wind (movie)
Gone with the Wind is the 1939 American movie based on Margaret Mitchell's book of the same name. It premiered in Atlanta, Georgia. It stars Clark Gable, Vivien Leigh, Leslie Howard and Olivia de Havilland. The movie tells the story of the American Civil War from the perspective (view point) of a young southern woman named Scarlett O'Hara.
Scarlett O'Hara is a spoiled, beautiful, histrionic young Southern woman living in Georgia in the year 1861. In this time, who a woman marries is very important to the rest of her life, and Scarlett loves only one man. His name is Ashley Wilkes. Unfortunately, Scarlett finds out that Ashley is going to marry a woman named Melanie Hamilton, his own cousin. During a barbecue at Ashley's plantation named Twelve Oaks, with all the families in the area, news arrives that a war between the Northern and Southern parts of the United States has begun. Before Scarlett lets Ashley marry Melanie, she decides to tell him how she really feels. While the women nap to before the upcoming party that evening, Scarlett slips down and waits for Ashley to come out of the "meeting" the men are having about the war.
During the meeting, Rhett Butler, a rich, clever, Charleston, South Carolina "gentleman", stands up to warn the men about being too sure of their victory in the war, explaining that the north has the technology, the rail lines, the immigrants they don't have. The men take insult, and Rhett leaves to let the men cool down. He decides to show himself around the house.
Ashley leaves the room as well, to be a good host. But, before he can catch up with him, Scarlett peeps out from her hiding place and waves Ashley over. He follows her into a room where they can be alone. Scarlett tells Ashley how much she loves him, but Ashley has already made up his mind to marry Melanie. The wealthy and spoiled Scarlett throws a fit, and because of that Ashley leaves the room. Scarlett in a frenzy picks up a vase and heaves it across the room over a couch and into the wall. The charming Rhett Butler rises from the couch, startling and embarrassing Scarlett. He agrees not to tell anyone about the conversation, although humorously mocking her about it all. Before the men leave, whooping at the excitement of war and declaring how they'll "whip those Yankees" and be back in a month, Scarlett agrees to marry Charles Hamilton (Melanie's younger brother). She barely looks at him, accepting his proposal only because she wants to get revenge on Ashley for marrying Melanie. Unfortunately, Charles gets sick and dies in the war, and Scarlett is left home bored with the traditions of mourning a man she didn't love.