1.
Braille
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Braille /ˈbreɪl/ is a tactile writing system used by people who are blind or visually impaired. It is traditionally written with embossed paper, braille-users can read computer screens and other electronic supports thanks to refreshable braille displays. They can write braille with the slate and stylus or type it on a braille writer, such as a portable braille note-taker. Braille is named after its creator, Frenchman Louis Braille, who lost his eyesight due to a childhood accident, in 1824, at the age of 15, Braille developed his code for the French alphabet as an improvement on night writing. He published his system, which included musical notation, in 1829. The second revision, published in 1837, was the first binary form of writing developed in the modern era, Braille characters are small rectangular blocks called cells that contain tiny palpable bumps called raised dots. The number and arrangement of these dots distinguish one character from another, since the various braille alphabets originated as transcription codes of printed writing systems, the mappings vary from language to language. Braille cells are not the thing to appear in braille text. There may be embossed illustrations and graphs, with the lines either solid or made of series of dots, arrows, bullets that are larger than braille dots, a full Braille cell includes six raised dots arranged in two lateral rows each having three dots. The dot positions are identified by numbers from one through six,64 solutions are possible from using one or more dots. A single cell can be used to represent a letter, number, punctuation mark. In the face of screen-reader software, braille usage has declined, in Barbiers system, sets of 12 embossed dots encoded 36 different sounds. It proved to be too difficult for soldiers to recognize by touch, in 1821 Barbier visited the Royal Institute for the Blind in Paris, where he met Louis Braille. Brailles solution was to use 6-dot cells and to assign a specific pattern to each letter of the alphabet. At first, braille was a transliteration of French orthography, but soon various abbreviations, contractions. The expanded English system, called Grade-2 Braille, was complete by 1905, for blind readers, Braille is an independent writing system, rather than a code of printed orthography. Braille is derived from the Latin alphabet, albeit indirectly, in Brailles original system, the dot patterns were assigned to letters according to their position within the alphabetic order of the French alphabet, with accented letters and w sorted at the end. The first ten letters of the alphabet, a–j, use the upper four dot positions and these stand for the ten digits 1–9 and 0 in a system parallel to Hebrew gematria and Greek isopsephy
2.
ASCII
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ASCII, abbreviated from American Standard Code for Information Interchange, is a character encoding standard. ASCII codes represent text in computers, telecommunications equipment, and other devices, most modern character-encoding schemes are based on ASCII, although they support many additional characters. ASCII was developed from telegraph code and its first commercial use was as a seven-bit teleprinter code promoted by Bell data services. Work on the ASCII standard began on October 6,1960, the first edition of the standard was published in 1963, underwent a major revision during 1967, and experienced its most recent update during 1986. Compared to earlier telegraph codes, the proposed Bell code and ASCII were both ordered for more convenient sorting of lists, and added features for other than teleprinters. Originally based on the English alphabet, ASCII encodes 128 specified characters into seven-bit integers as shown by the ASCII chart above. The characters encoded are numbers 0 to 9, lowercase letters a to z, uppercase letters A to Z, basic punctuation symbols, control codes that originated with Teletype machines, for example, lowercase j would become binary 1101010 and decimal 106. ASCII includes definitions for 128 characters,33 are non-printing control characters that affect how text and space are processed and 95 printable characters, of these, the IANA encourages use of the name US-ASCII for Internet uses of ASCII. The ASA became the United States of America Standards Institute and ultimately the American National Standards Institute, there was some debate at the time whether there should be more control characters rather than the lowercase alphabet. The X3.2.4 task group voted its approval for the change to ASCII at its May 1963 meeting, the X3 committee made other changes, including other new characters, renaming some control characters and moving or removing others. ASCII was subsequently updated as USAS X3. 4-1967, then USAS X3. 4-1968, ANSI X3. 4-1977 and they proposed a 9-track standard for magnetic tape, and attempted to deal with some punched card formats. The X3.2 subcommittee designed ASCII based on the earlier teleprinter encoding systems, like other character encodings, ASCII specifies a correspondence between digital bit patterns and character symbols. This allows digital devices to communicate each other and to process, store. Before ASCII was developed, the encodings in use included 26 alphabetic characters,10 numerical digits, ITA2 were in turn based on the 5-bit telegraph code Émile Baudot invented in 1870 and patented in 1874. The committee debated the possibility of a function, which would allow more than 64 codes to be represented by a six-bit code. In a shifted code, some character codes determine choices between options for the character codes. It allows compact encoding, but is reliable for data transmission. The standards committee decided against shifting, and so ASCII required at least a seven-bit code, the committee considered an eight-bit code, since eight bits would allow two four-bit patterns to efficiently encode two digits with binary-coded decimal
3.
Asterisk
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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 also 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,
4.
0 (number)
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0 is both a number and the numerical digit used to represent that number in numerals. The number 0 fulfills a role in mathematics as the additive identity of the integers, real numbers. As a digit,0 is used as a placeholder in place value systems, names for the number 0 in English include zero, nought or naught, nil, or—in contexts where at least one adjacent digit distinguishes it from the letter O—oh or o. Informal or slang terms for zero include zilch and zip, ought and aught, as well as cipher, have also been used historically. The word zero came into the English language via French zéro from Italian zero, in pre-Islamic time the word ṣifr had the meaning empty. Sifr evolved to mean zero when it was used to translate śūnya from India, the first known English use of zero was in 1598. The Italian mathematician Fibonacci, who grew up in North Africa and is credited with introducing the system to Europe. This became zefiro in Italian, and was contracted to zero in Venetian. The Italian word zefiro was already in existence and may have influenced the spelling when transcribing Arabic ṣifr, modern usage There are different words used for the number or concept of zero depending on the context. For the simple notion of lacking, the words nothing and none are often used, sometimes the words nought, naught and aught are used. Several sports have specific words for zero, such as nil in football, love in tennis and it is often called oh in the context of telephone numbers. Slang words for zero include zip, zilch, nada, duck egg and goose egg are also slang for zero. Ancient Egyptian numerals were base 10 and they used hieroglyphs for the digits and were not positional. By 1740 BC, the Egyptians had a symbol for zero in accounting texts. The symbol nfr, meaning beautiful, was used to indicate the base level in drawings of tombs and pyramids. By the middle of the 2nd millennium BC, the Babylonian mathematics had a sophisticated sexagesimal positional numeral system, the lack of a positional value was indicated by a space between sexagesimal numerals. By 300 BC, a symbol was co-opted as a placeholder in the same Babylonian system. In a tablet unearthed at Kish, the scribe Bêl-bân-aplu wrote his zeros with three hooks, rather than two slanted wedges, the Babylonian placeholder was not a true zero because it was not used alone
5.
1 (number)
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1, is a number, a numeral, and the name of the glyph representing that number. It represents a single entity, the unit of counting or measurement, for example, a line segment of unit length is a line segment of length 1. It is also the first of the series of natural numbers. The word one can be used as a noun, an adjective and it comes from the English word an, which comes from the Proto-Germanic root *ainaz. The Proto-Germanic root *ainaz comes from the Proto-Indo-European root *oi-no-, compare the Proto-Germanic root *ainaz to Old Frisian an, Gothic ains, Danish een, Dutch een, German eins and Old Norse einn. Compare the Proto-Indo-European root *oi-no- to Greek oinos, Latin unus, Old Persian aivam, Old Church Slavonic -inu and ino-, Lithuanian vienas, Old Irish oin, One, sometimes referred to as unity, is the first non-zero natural number. It is thus the integer before two and after zero, and the first positive odd number, any number multiplied by one is that number, as one is the identity for multiplication. As a result,1 is its own factorial, its own square, its own cube, One is also the result of the empty product, as any number multiplied by one is itself. It is also the natural number that is neither composite nor prime with respect to division. The Gupta wrote it as a line, and the Nagari sometimes added a small circle on the left. The Nepali also rotated it to the right but kept the circle small and this eventually became the top serif in the modern numeral, but the occasional short horizontal line at the bottom probably originates from similarity with the Roman numeral I. Where the 1 is written with an upstroke, the number 7 has a horizontal stroke through the vertical line. While the shape of the 1 character has an ascender in most modern typefaces, in typefaces with text figures, many older typewriters do not have a separate symbol for 1 and use the lowercase letter l instead. It is possible to find cases when the uppercase J is used,1 cannot be used as the base of a positional numeral system, as the only digit that would be permitted in such a system would be 0. Since the base 1 exponential function always equals 1, its inverse does not exist, there are two ways to write the real number 1 as a recurring decimal, as 1.000. and as 0.999. There is only one way to represent the real number 1 as a Dedekind cut, in a multiplicative group or monoid, the identity element is sometimes denoted 1, but e is also traditional. However,1 is especially common for the identity of a ring. When such a ring has characteristic n not equal to 0,1 is the first figurate number of every kind, such as triangular number, pentagonal number and centered hexagonal number, to name just a few
6.
2 (number)
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2 is a number, numeral, and glyph. It is the number following 1 and preceding 3. The number two has many properties in mathematics, an integer is called even if it is divisible by 2. For integers written in a system based on an even number, such as decimal and hexadecimal. If it is even, then the number is even. In particular, when written in the system, all multiples of 2 will end in 0,2,4,6. In numeral systems based on an odd number, divisibility by 2 can be tested by having a root that is even. Two is the smallest and first prime number, and the only prime number. Two and three are the two consecutive prime numbers. 2 is the first Sophie Germain prime, the first factorial prime, the first Lucas prime, the first Ramanujan prime, and it is an Eisenstein prime with no imaginary part and real part of the form 3n −1. It is also a Stern prime, a Pell number, the first Fibonacci prime, and it is the third Fibonacci number, and the second and fourth Perrin numbers. Despite being prime, two is also a highly composite number, because it is a natural number which has more divisors than any other number scaled relative to the number itself. The next superior highly composite number is six, vulgar fractions with only 2 or 5 in the denominator do not yield infinite decimal expansions, as is the case with all other primes, because 2 and 5 are factors of ten, the decimal base. Two is the number x such that the sum of the reciprocals of the powers of x equals itself. In symbols ∑ k =0 ∞12 k =1 +12 +14 +18 +116 + ⋯ =2. This comes from the fact that, ∑ k =0 ∞1 n k =1 +1 n −1 for all n ∈ R >1, powers of two are central to the concept of Mersenne primes, and important to computer science. Two is the first Mersenne prime exponent, the square root of 2 was the first known irrational number. The smallest field has two elements, in the set-theoretical construction of the natural numbers,2 is identified with the set
7.
3 (number)
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3 is a number, numeral, and glyph. It is the number following 2 and preceding 4. Three is the largest number still written with as many lines as the number represents, to this day 3 is written as three lines in Roman and Chinese numerals. This was the way the Brahmin Indians wrote it, and the Gupta made the three lines more curved, the Nagari started rotating the lines clockwise and ending each line with a slight downward stroke on the right. Eventually they made these strokes connect with the lines below, and it was the Western Ghubar Arabs who finally eliminated the extra stroke and created our modern 3. ٣ While the shape of the 3 character has an ascender in most modern typefaces, in typefaces with text figures the character usually has a descender, as, for example, in some French text-figure typefaces, though, it has an ascender instead of a descender. A common variant of the digit 3 has a flat top and this form is sometimes used to prevent people from fraudulently changing a 3 into an 8. It is usually found on UPC-A barcodes and standard 52-card decks,3 is, a rough approximation of π and a very rough approximation of e when doing quick estimates. The first odd prime number, and the second smallest prime, the only number that is both a Fermat prime and a Mersenne prime. The first unique prime due to the properties of its reciprocal, the second triangular number and it is the only prime triangular number. Both the zeroth and third Perrin numbers in the Perrin sequence, the smallest number of sides that a simple polygon can have. The only prime which is one less than a perfect square, any other number which is n2 −1 for some integer n is not prime, since it is. This is true for 3 as well, but in case the smaller factor is 1. If n is greater than 2, both n −1 and n +1 are greater than 1 so their product is not prime, the number of non-collinear points needed to determine a plane and a circle. Also, Vulgar fractions with 3 in the denominator have a single digit repeating sequences in their decimal expansions,0.000, a natural number is divisible by three if the sum of its digits in base 10 is divisible by 3. For example, the number 21 is divisible by three and the sum of its digits is 2 +1 =3, because of this, the reverse of any number that is divisible by three is also divisible by three. For instance,1368 and its reverse 8631 are both divisible by three and this works in base 10 and in any positional numeral system whose base divided by three leaves a remainder of one. Three of the five regular polyhedra have triangular faces – the tetrahedron, the octahedron, also, three of the five regular polyhedra have vertices where three faces meet – the tetrahedron, the hexahedron, and the dodecahedron
8.
4 (number)
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4 is a number, numeral, and glyph. It is the number following 3 and preceding 5. Four is the only cardinal numeral in the English language that has the number of letters as its number value. Four is the smallest composite number, its divisors being 1 and 2. Four is also a composite number. The next highly composite number is 6, Four is the second square number, the second centered triangular number. 4 is the smallest squared prime and the even number in this form. It has a sum of 3 which is itself prime. The aliquot sequence of 4 has 4 members and is accordingly the first member of the 3-aliquot tree, a number is a multiple of 4 if its last two digits are a multiple of 4. For example,1092 is a multiple of 4 because 92 =4 ×23, only one number has an aliquot sum of 4 and that is squared prime 9. Four is the smallest composite number that is equal to the sum of its prime factors, however, it is the only composite number n for which. It is also a Motzkin number, in bases 6 and 12,4 is a 1-automorphic number. In addition,2 +2 =2 ×2 =22 =4, continuing the pattern in Knuths up-arrow notation,2 ↑↑2 =2 ↑↑↑2 =4, and so on, for any number of up arrows. A four-sided plane figure is a quadrilateral which include kites, rhombi, a circle divided by 4 makes right angles and four quadrants. Because of it, four is the number of plane. Four cardinal directions, four seasons, duodecimal system, and vigesimal system are based on four, a solid figure with four faces as well as four vertices is a tetrahedron, and 4 is the smallest possible number of faces of a polyhedron. The regular tetrahedron is the simplest Platonic solid, a tetrahedron, which can also be called a 3-simplex, has four triangular faces and four vertices. It is the only regular polyhedron
9.
5 (number)
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5 is a number, numeral, and glyph. It is the number following 4 and preceding 6. Five is the prime number. Because it can be written as 221 +1, five is classified as a Fermat prime, therefore a regular polygon with 5 sides is constructible with compass and unmarked straightedge. 5 is the third Sophie Germain prime, the first safe prime, the third Catalan number, Five is the first Wilson prime and the third factorial prime, also an alternating factorial. Five is the first good prime and it is an Eisenstein prime with no imaginary part and real part of the form 3n −1. It is also the number that is part of more than one pair of twin primes. Five is conjectured to be the only odd number and if this is the case then five will be the only odd prime number that is not the base of an aliquot tree. Five is also the only prime that is the sum of two primes, namely 2 and 3. The number 5 is the fifth Fibonacci number, being 2 plus 3,5 is also a Pell number and a Markov number, appearing in solutions to the Markov Diophantine equation. Whereas 5 is unique in the Fibonacci sequence, in the Perrin sequence 5 is both the fifth and sixth Perrin numbers,5 is the length of the hypotenuse of the smallest integer-sided right triangle. In bases 10 and 20,5 is a 1-automorphic number,5 and 6 form a Ruth–Aaron pair under either definition. There are five solutions to Známs problem of length 6 and this is related to the fact that the symmetric group Sn is a solvable group for n ≤4 and not solvable for n ≥5. While all graphs with 4 or fewer vertices are planar, there exists a graph with 5 vertices which is not planar, K5, Five is also the number of Platonic solids. A polygon with five sides is a pentagon, figurate numbers representing pentagons are called pentagonal numbers. Five is also a square pyramidal number, Five is the only prime number to end in the digit 5, because all other numbers written with a 5 in the ones-place under the decimal system are multiples of five. As a consequence of this,5 is in base 10 a 1-automorphic number, vulgar fractions with 5 or 2 in the denominator do not yield infinite decimal expansions, unlike expansions with all other prime denominators, because they are prime factors of ten, the base. When written in the system, all multiples of 5 will end in either 5 or 0
10.
6 (number)
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6 is the natural number following 5 and preceding 7. The SI prefix for 10006 is exa-, and for its reciprocal atto-,6 is the smallest positive integer which is neither a square number nor a prime number. Six is the second smallest composite number, its proper divisors are 1,2 and 3, since six equals the sum of its proper divisors, six is the smallest perfect number, Granville number, and S -perfect number. As a perfect number,6 is related to the Mersenne prime 3,6 is the only even perfect number that is not the sum of successive odd cubes. As a perfect number,6 is the root of the 6-aliquot tree, and is itself the sum of only one number. Six is the number that is both the sum and the product of three consecutive positive numbers. Unrelated to 6 being a number, a Golomb ruler of length 6 is a perfect ruler. Six is the first discrete biprime and the first member of the discrete biprime family, Six is the smallest natural number that can be written as the sum of two positive rational cubes which are not integers,6 =3 +3. Six is a perfect number, a harmonic divisor number and a superior highly composite number. The next superior highly composite number is 12,5 and 6 form a Ruth-Aaron pair under either definition. There are no Graeco-Latin squares with order 6, if n is a natural number that is not 2 or 6, then there is a Graeco-Latin square with order n. The smallest non-abelian group is the symmetric group S3 which has 3, s6, with 720 elements, is the only finite symmetric group which has an outer automorphism. This automorphism allows us to construct a number of mathematical objects such as the S Steiner system, the projective plane of order 4. This can also be expressed category theoretically, consider the category whose objects are the n element sets and this category has a non-trivial functor to itself only for n =6. 6 similar coins can be arranged around a central coin of the radius so that each coin makes contact with the central one. This makes 6 the answer to the kissing number problem. The densest sphere packing of the plane is obtained by extending this pattern to the lattice in which each circle touches just six others. 6 is the largest of the four all-Harshad numbers, a six-sided polygon is a hexagon, one of the three regular polygons capable of tiling the plane
11.
7 (number)
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7 is the natural number following 6 and preceding 8. Seven, the prime number, is not only a Mersenne prime. It is also a Newman–Shanks–Williams prime, a Woodall prime, a prime, a lucky prime, a happy number, a safe prime. Seven is the lowest natural number that cannot be represented as the sum of the squares of three integers, Seven is the aliquot sum of one number, the cubic number 8 and is the base of the 7-aliquot tree. N =7 is the first natural number for which the statement does not hold, Two nilpotent endomorphisms from Cn with the same minimal polynomial. 7 is the only number D for which the equation 2n − D = x2 has more than two solutions for n and x natural, in particular, the equation 2n −7 = x2 is known as the Ramanujan–Nagell equation. 7 is the dimension, besides the familiar 3, in which a vector cross product can be defined. 7 is the lowest dimension of an exotic sphere, although there may exist as yet unknown exotic smooth structures on the 4-dimensional sphere. 999,999 divided by 7 is exactly 142,857, for example, 1/7 =0.142857142857. and 2/7 =0.285714285714. In fact, if one sorts the digits in the number 142857 in ascending order,124578, the remainder of dividing any number by 7 will give the position in the sequence 124578 that the decimal part of the resulting number will start. For example,628 ÷7 =89 5/7, here 5 is the remainder, so in this case,628 ÷7 =89.714285. Another example,5238 ÷7 =748 2/7, hence the remainder is 2, in this case,5238 ÷7 =748.285714. A seven-sided shape is a heptagon, the regular n-gons for n ≤6 can be constructed by compass and straightedge alone, but the regular heptagon cannot. Figurate numbers representing heptagons are called heptagonal numbers, Seven is also a centered hexagonal number. Seven is the first integer reciprocal with infinitely repeating sexagesimal representation, There are seven frieze groups, the groups consisting of symmetries of the plane whose group of translations is isomorphic to the group of integers. There are seven types of catastrophes. When rolling two standard six-sided dice, seven has a 6 in 36 probability of being rolled, the greatest of any number, the Millennium Prize Problems are seven problems in mathematics that were stated by the Clay Mathematics Institute in 2000. Currently, six of the problems remain unsolved, in quaternary,7 is the smallest prime with a composite sum of digits
12.
8 (number)
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8 is the natural number following 7 and preceding 9. 8 is, a number, its proper divisors being 1,2. It is twice 4 or four times 2, a power of two, being 23, and is the first number of the form p3, p being an integer greater than 1. The first number which is neither prime nor semiprime, the base of the octal number system, which is mostly used with computers. In octal, one digit represents 3 bits, in modern computers, a byte is a grouping of eight bits, also called an octet. A Fibonacci number, being 3 plus 5, the next Fibonacci number is 13. 8 is the only positive Fibonacci number, aside from 1, the order of the smallest non-abelian group all of whose subgroups are normal. The dimension of the octonions and is the highest possible dimension of a division algebra. The first number to be the sum of two numbers other than itself, the discrete biprime 10, and the square number 49. It has a sum of 7 in the 4 member aliquot sequence being the first member of 7-aliquot tree. All powers of 2, have a sum of one less than themselves. A number is divisible by 8 if its last 3 digits,8 and 9 form a Ruth–Aaron pair under the second definition in which repeated prime factors are counted as often as they occur. There are a total of eight convex deltahedra, a polygon with eight sides is an octagon. Figurate numbers representing octagons are called octagonal numbers, a polyhedron with eight faces is an octahedron. A cuboctahedron has as faces six equal squares and eight regular triangles. Sphenic numbers always have exactly eight divisors, the number 8 is involved with a number of interesting mathematical phenomena related to the notion of Bott periodicity. For example, if O is the limit of the inclusions of real orthogonal groups O ↪ O ↪ … ↪ O ↪ …. Clifford algebras also display a periodicity of 8, for example, the algebra Cl is isomorphic to the algebra of 16 by 16 matrices with entries in Cl
13.
9 (number)
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9 is the natural number following 8 and preceding 10. In the NATO phonetic alphabet, the digit 9 is called Niner, five-digit produce PLU codes that begin with 9 are organic. Common terminal digit in psychological pricing, Nine is a number that appears often in Indian Culture and mythology. Nine influencers are attested in Indian astrology, in the Vaisheshika branch of Hindu philosophy, there are nine universal substances or elements, Earth, Water, Air, Fire, Ether, Time, Space, Soul, and Mind. Navaratri is a festival dedicated to the nine forms of Durga. Navaratna, meaning 9 jewels may also refer to Navaratnas - accomplished courtiers, Navratan - a kind of dish, according to Yoga, the human body has nine doors - two eyes, two ears, the mouth, two nostrils, and the openings for defecation and procreation. In Indian aesthetics, there are nine kinds of Rasa, Nine is considered a good number in Chinese culture because it sounds the same as the word long-lasting. Nine is strongly associated with the Chinese dragon, a symbol of magic, there are nine forms of the dragon, it is described in terms of nine attributes, and it has nine children. It has 117 scales –81 yang and 36 yin, all three numbers are multiples of 9 as well as having the same digital root of 9. The dragon often symbolizes the Emperor, and the number nine can be found in many ornaments in the Forbidden City, the name of the area called Kowloon in Hong Kong literally means, nine dragons. The nine-dotted line delimits certain island claims by China in the South China Sea, the nine-rank system was a civil service nomination system used during certain Chinese dynasties. 9 Points of the Heart / Heart Master Channels in Traditional Chinese Medicine, the nine bows is a term used in Ancient Egypt to represent the traditional enemies of Egypt. The Ennead is a group of nine Egyptian deities, who, in versions of the Osiris myth. The Nine Worthies are nine historical, or semi-legendary figures who, in Norse mythology, the universe is divided into nine worlds which are all connected by the world tree Yggdrasil. The nine Muses in Greek mythology are Calliope, Clio, Erato, Euterpe, Melpomene, Polyhymnia, Terpsichore, Thalia and it takes nine days to fall from heaven to earth, and nine more to fall from earth to Tartarus—a place of torment in the underworld. Leto labored for nine days and nine nights for Apollo, according to the Homeric Hymn to Delian Apollo, according to Georges Ifrah, the origin of the 9 integers can be attributed to ancient Indian civilization, and was adopted by subsequent civilizations in conjunction with the 0. In the beginning, various Indians wrote 9 similar to the modern closing question mark without the bottom dot, the Kshatrapa, Andhra and Gupta started curving the bottom vertical line coming up with a 3-look-alike. The Nagari continued the bottom stroke to make a circle and enclose the 3-look-alike, as time went on, the enclosing circle became bigger and its line continued beyond the circle downwards, as the 3-look-alike became smaller
14.
Less-than sign
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The less-than sign is a sign of inequality. The less-than symbol is used in operations that usually pertain to work being done mathematically or with a programming language. The symbol looks similar to a sideways V and is used to show inequality between two numbers or expressions. The symbol can also be used to the left of a number to denote the concept of any lesser number. There are other combinations of the symbol and the equals symbols which are also used mathematically and computationally. The less-than sign is an original ASCII character, the less-than sign is used for an approximation of the opening angle bracket. ASCII does not have angle brackets, in BASIC, Lisp-family languages, and C-family languages, operator < means less than. Means less than, later versions allow <, in Bourne shell, operator -lt means less than. The double less-than sign is used for an approximation of the sign or of the opening guillemet. ASCII does not have much-less-than sign, in Bash, Perl, and Ruby, operator <<EOF is used to denote the beginning of a here document. In C and C++, operator << represents a left shift. In the C++ Standard Library, operator <<, when applied on a stream, acts as insertion operator. The less-than sign plus the equals sign is used for an approximation of the less-than-or-equal-to sign, ASCII does not have a less-than-or-equal-to sign, but Unicode defines it at codepoint U+2264. In BASIC, Lisp-family languages, and C-family languages, operator <= means less than or equal to, in Sinclair BASIC it is encoded as a single-byte code point token. Means less than or equal to, in Bourne shell and Windows PowerShell, the operator -le means less than or equal to. In Bourne shell, less-than sign is used to input from a file. Less-than plus ampersand is used to redirect from a file descriptor, less-than sign is used in the spaceship operator. In HTML, the sign is used at the beginning of tags
15.
Greater-than sign
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The greater-than symbol is used in various operations that usually pertain to work being done mathematically or with a programming language. The symbol looks similar to a sideways V and has used in recorded literature as old as the 1560s. Generally, the symbol is used to show inequality between two numbers or expressions, there are other combinations of the greater-than symbol and the equals symbol or the greater-than symbol beside another greater-than symbol that are also used mathematically and computationally. The symbols < and > first appear in Artis Analyticae Praxis ad Aequationes Algebraicas Resolvendas by Thomas Harriot, the text states, Signum majoritatis ut a > b significet a majorem quam b and Signum minoritatis ut a < b significet a minorem quam b. According to Johnson, while Harriot was surveying North America, he saw a Native American with a symbol that resembled the greater than symbol both backwards and forwards, Johnson says it is likely he developed the two symbols from this symbol. The greater-than sign is an original ASCII character, the character in Unicode is U+003E > gt, this is inherited from the same value in ASCII. Apart from this, Unicode also has the variants, U+232A 〉 RIGHT-POINTING ANGLE BRACKET The greater-than sign is used for an approximation of the closing angle bracket. ASCII does not have angular brackets, BASIC and C-family languages, use the operator > to mean greater than. In Lisp-family languages, > is a used to mean greater than. The double greater-than sign is used for an approximation of the greater than sign. ASCII does not have the much greater-than sign, the double greater-than sign is also used for an approximation of the closing guillemet. In Java, C, and C++, the operator >> is the right-shift operator, in C++ it is also used to get input from a stream, similar to the C functions getchar and fgets. In Haskell, the >> function is a monadic operator and it is used for sequentially composing two actions, discarding any value produced by the first. In that regard, it is like the statement sequencing operator in imperative languages, ASCII doesnt have a greater-than-or-equal-to sign. In BASIC, Lisp-family languages, and C-family languages, operator >= means greater than or equal to, in Sinclair BASIC it is encoded as a single-byte code point token. Means greater than or equal to, in Bourne shell and Windows PowerShell, the operator -ge means greater than or equal to. In some programming languages, the sign is used in conjunction with a hyphen-minus to create an arrow. Arrows like these could also be used in text where other arrow symbols are unavailable, in Bourne shell, greater-than sign is used to redirect output to a file
16.
A
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A is the first letter and the first vowel in the ISO basic Latin alphabet. It is similar to the Ancient Greek letter alpha, from which it derives, the upper-case version consists of the two slanting sides of a triangle, crossed in the middle by a horizontal bar. The lower-case version can be written in two forms, the double-storey a and single-storey ɑ, the latter is commonly used in handwriting and fonts based on it, especially fonts intended to be read by children, and is also found in italic type. The earliest certain ancestor of A is aleph, the first letter of the Phoenician alphabet, in turn, the ancestor of aleph may have been a pictogram of an ox head in proto-Sinaitic script influenced by Egyptian hieroglyphs, styled as a triangular head with two horns extended. The Phoenician alphabet letter had a form that served as the base for some later forms. Its name is thought to have corresponded closely to the Hebrew or Arabic aleph, the Etruscans brought the Greek alphabet to their civilization in the Italian Peninsula and left the letter unchanged. During Roman times, there were many variant forms of the letter A, first was the monumental or lapidary style, which was used when inscribing on stone or other permanent mediums. There was also a style used for everyday or utilitarian writing. Variants also existed that were intermediate between the monumental and cursive styles, the known variants include the early semi-uncial, the uncial, and the later semi-uncial. At the end of the Roman Empire, several variants of the cursive minuscule developed through Western Europe. By the 9th century, the Caroline script, which was similar to the present-day form, was the principal form used in book-making. This form was derived through a combining of prior forms, 15th-century Italy saw the formation of the two main variants that are known today. These variants, the Italic and Roman forms, were derived from the Caroline Script version, the Italic form, also called script a, is used in most current handwriting and consists of a circle and vertical stroke. This slowly developed from the fifth-century form resembling the Greek letter tau in the hands of medieval Irish and English writers, the Roman form is used in most printed material, it consists of a small loop with an arc over it. Both derive from the majuscule form, in Greek handwriting, it was common to join the left leg and horizontal stroke into a single loop, as demonstrated by the uncial version shown. Many fonts then made the right leg vertical, in some of these, the serif that began the right leg stroke developed into an arc, resulting in the printed form, while in others it was dropped, resulting in the modern handwritten form. Italic type is used to mark emphasis or more generally to distinguish one part of a text from the rest. There are some other cases aside from italic type where script a, the double ⟨aa⟩ sequence does not occur in native English words, but is found in some words derived from foreign languages such as Aaron and aardvark
17.
D
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D is the fourth letter of the modern English alphabet and the ISO basic Latin alphabet. The Semitic letter Dāleth may have developed from the logogram for a fish or a door, there are many different Egyptian hieroglyphs that might have inspired this. In Semitic, Ancient Greek and Latin, the letter represented /d/, in the Etruscan alphabet the letter was superfluous, the equivalent Greek letter is Delta, Δ. The minuscule form of d consists of a loop and a vertical stroke. It developed by gradual variations on the majuscule form, in handwriting, it was common to start the arc to the left of the vertical stroke, resulting in a serif at the top of the arc. This serif was extended while the rest of the letter was reduced, resulting in an angled stroke, the angled stroke slowly developed into a vertical stroke. In most languages that use the Latin alphabet, and in the International Phonetic Alphabet, however, in the Vietnamese alphabet, it represents the sound /z/ in northern dialects or /j/ in southern dialects. In Fijian it represents a prenasalized stop /nd/, in some languages where voiceless unaspirated stops contrast with voiceless aspirated stops, ⟨d⟩ represents an unaspirated /t/, while ⟨t⟩ represents an aspirated /tʰ/. Examples of such languages include Icelandic, Scottish Gaelic, Navajo, the Roman numeral Ⅾ represents the number 500. D is the grade below C but above E in the grading system. The dictionary definition of D at Wiktionary The dictionary definition of d at Wiktionary
18.
E
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E is the fifth letter and the second vowel in the modern English alphabet and the ISO basic Latin alphabet. It is the most commonly used letter in many languages, including Czech, Danish, Dutch, English, French, German, Hungarian, Latin, Latvian, Norwegian, Spanish, the Latin letter E differs little from its source, the Greek letter epsilon, Ε. In Semitic, the letter represented /h/, in Greek, hê became the letter epsilon, the various forms of the Old Italic script and the Latin alphabet followed this usage. Although Middle English spelling used ⟨e⟩ to represent long and short /e/, in other cases, the letter is silent, generally at the end of words. In the orthography of languages it represents either these or /ɛ/, or some variation of these sounds. Less commonly, as in French, German, or Saanich, ⟨e⟩ represents a mid-central vowel /ə/. Digraphs with ⟨e⟩ are common to indicate either diphthongs or monophthongs, such as ⟨ea⟩ or ⟨ee⟩ for /iː/ or /eɪ/ in English, ⟨ei⟩ for /aɪ/ in German, the International Phonetic Alphabet uses ⟨e⟩ for the close-mid front unrounded vowel or the mid front unrounded vowel. E is the most common letter in the English alphabet and several other European languages, in the story The Gold Bug by Edgar Allan Poe, a character figures out a random character code by remembering that the most used letter in English is E. This makes it a hard and popular letter to use when writing lipograms, ernest Vincent Wrights Gadsby is considered a dreadful novel, and supposedly at least part of Wrights narrative issues were caused by language limitations imposed by the lack of E. Both Georges Perecs novel A Void and its English translation by Gilbert Adair omit e and are considered better works, ∃, existential quantifier in predicate logic. ∈, the symbol for set membership in set theory, ℯ, the base of the natural logarithm. 1 Also for encodings based on ASCII, including the DOS, Windows, ISO-8859 and Macintosh families of encodings. In British Sign Language, the e is signed by extending the index finger of the right hand touching the tip of index on the left hand. Media related to E at Wikimedia Commons The dictionary definition of E at Wiktionary The dictionary definition of e at Wiktionary
19.
F
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F is the sixth letter in the modern English alphabet and the ISO basic Latin alphabet. The origin of F is the Semitic letter vâv that represented a sound like /v/ or /w/, graphically it originally probably depicted either a hook or a club. Latin F, despite being pronounced differently, is descended from digamma. After sound changes eliminated /w/ from spoken Greek, digamma was used only as a numeral, however, the Greek alphabet also gave rise to other alphabets, and some of these retained letters descended from digamma. In the Etruscan alphabet, F probably represented /w/, as in Greek, when the Romans adopted the alphabet, they used V not only for the vowel /u/, but also for the corresponding semivowel /w/, leaving F available for /f/. And so out of the various vav variants in the Mediterranean world, the Roman alphabet forms the basis of the alphabet used today for English and many other languages. The lowercase f is not related to the visually similar long s, ſ, the use of the long s largely died out by the beginning of the 19th century, mostly to prevent confusion with f when using a short mid-bar. In the English writing system ⟨f⟩ is used to represent the sound /f/ and it is commonly doubled at the end of words. Exceptionally, it represents the voiced labiodental fricative /v/ in the word of. In the writing systems of languages, ⟨f⟩ commonly represents /f/. In French orthography, ⟨f⟩ is used to represent /f/ and it may also be silent at the end of words. In Spanish orthography, ⟨f⟩ is used to represent /f/, in the Hepburn romanization of Japanese, ⟨f⟩ is used to represent. This sound is considered to be an allophone of /h/. In Welsh orthography, ⟨f⟩ represents /v/ while ⟨ff⟩ represents /f/, in Slavic languages, ⟨f⟩ is used primarily in words of foreign origin. The International Phonetic Alphabet uses ⟨f⟩ to represent the labiodental fricative. Media related to F at Wikimedia Commons The dictionary definition of F at Wiktionary The dictionary definition of f at Wiktionary
20.
G
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G is the 7th letter in the ISO basic Latin alphabet. The letter G was introduced in the Old Latin period as a variant of C to distinguish voiced /ɡ/ from voiceless /k/, the recorded originator of G is freedman Spurius Carvilius Ruga, the first Roman to open a fee-paying school, who taught around 230 BC. At this time, K had fallen out of favor, and C, rugas positioning of G shows that alphabetic order related to the letters values as Greek numerals was a concern even in the 3rd century BC. Hempl proposes that there never was such a space in the alphabet, zeta took shapes like ⊏ in some of the Old Italic scripts, the development of the monumental form G from this shape would be exactly parallel to the development of C from gamma. He suggests that the pronunciation /k/ > /ɡ/ was due to contamination from the also similar-looking K, because of French influence, English orthography shares this feature. The modern lowercase g has two variants, the single-story and the double-story. The double-story form had developed similarly, except that some ornate forms then extended the tail back to the right, the initial extension to the left was absorbed into the upper closed bowl. The double-story version became popular when printing switched to Roman type because the tail was effectively shorter, in the double-story version, a small top stroke in the upper-right, often terminating in an orb shape, is called an ear. Generally, the two forms are complementary, but occasionally the difference has been exploited to provide contrast. Most, if not all, in English, the letter appears either alone or in some digraphs. In words of Romance origin, ⟨g⟩ is mainly soft before ⟨e⟩, ⟨i⟩, or ⟨y⟩, and hard otherwise. There are many English words of non-Romance origin where ⟨g⟩ is hard though followed by ⟨e⟩ or ⟨i⟩, the double consonant ⟨gg⟩ has the value /ɡ/ as in nugget, with very few exceptions, /gd͡ʒ/ in suggest and /d͡ʒ/ in exaggerate and veggies. The digraph ⟨dg⟩ has the value /d͡ʒ/, as in badger, non-digraph ⟨dg⟩ can also occur, in compounds like floodgate and headgear. Non-trigraph ⟨ngh⟩ also occurs, in compounds like stronghold and dunghill, Most Romance languages and some Nordic languages also have two main pronunciations for ⟨g⟩, hard and soft. While the soft value of ⟨g⟩ varies in different Romance languages, in all except Romanian and Italian, in Italian and Romanian, ⟨gh⟩ is used to represent /ɡ/ before front vowels where ⟨g⟩ would otherwise represent a soft value. In Italian and French, ⟨gn⟩ is used to represent the palatal nasal /ɲ/, in Italian, the trigraph ⟨gli⟩, when appearing before a vowel or as the article and pronoun gli, represents the palatal lateral approximant /ʎ/. Other languages typically use ⟨g⟩ to represent /ɡ/ regardless of position, amongst European languages Czech, Dutch and Finnish are an exception as they do not have /ɡ/ in their native words. Nevertheless, word-finally it is always voiceless in all dialects, including the standard Dutch of Belgium, on the other hand, some dialects, may have a phonemic /ɡ/. Faroese uses ⟨g⟩ to represent /dʒ/, in addition to /ɡ/, in Maori, ⟨g⟩ is used in the digraph ⟨ng⟩ which represents the velar nasal /ŋ/ and is pronounced like the ⟨ng⟩ in singer
21.
H
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H is the eighth letter in the ISO basic Latin alphabet. The original Semitic letter Heth most likely represented the voiceless pharyngeal fricative, the form of the letter probably stood for a fence or posts. The Greek eta Η in Archaic Greek alphabets still represented /h/, in this context, the letter eta is also known as heta to underline this fact. Thus, in the Old Italic alphabets, the letter heta of the Euboean alphabet was adopted with its sound value /h/. For most English speakers, the name for the letter is pronounced as /ˈeɪtʃ/, the pronunciation /ˈheɪtʃ/ and the associated spelling haitch is often considered to be h-adding and is considered nonstandard in England. It is, however, a feature of Hiberno-English and other varieties of English, such as those of Malaysia, India, Newfoundland, in Northern Ireland, it is a shibboleth as Protestant schools teach aitch and Catholics haitch. In the Republic of Ireland, the h is generally pronounced as haitch. The perceived name of the letter affects the choice of indefinite article before initialisms beginning with H, the pronunciation /ˈheɪtʃ/ may be a hypercorrection formed by analogy with the names of the other letters of the alphabet, most of which include the sound they represent. Despite this increasing number, pronunciation without the /h/ sound is considered to be standard in England. Authorities disagree about the history of the letters name, the Oxford English Dictionary says the original name of the letter was in Latin, this became in Vulgar Latin, passed into English via Old French, and by Middle English was pronounced. The American Heritage Dictionary of the English Language derives it from French hache from Latin haca or hic, anatoly Liberman suggests a conflation of two obsolete orderings of the alphabet, one with H immediately followed by K and the other without any K, reciting the formers. H, K, L. as when reinterpreted for the latter, H, L. would imply a pronunciation for H. In English, ⟨h⟩ occurs as a single-letter grapheme and in digraphs, such as ⟨ch⟩ /tʃ/, /ʃ/, /k/, or /x/). The letter is silent in a syllable rime, as in ah, ohm, dahlia, cheetah, pooh-poohed, as well as in other words such as hour, honest, herb. Initial /h/ is often not pronounced in the form of some function words including had, has, have, he, her, him, his. It was formerly common for an rather than a to be used as the article before a word beginning with /h/ in an unstressed syllable, as in an historian. In the German language, the name of the letter is pronounced /haː/, following a vowel, it often silently indicates that the vowel is long, In the word erhöhen, only the first ⟨h⟩ represents /h/. In 1901, a spelling reform eliminated the silent ⟨h⟩ in nearly all instances of ⟨th⟩ in native German words such as thun or Thür
22.
K
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K is the eleventh letter of the modern English alphabet and the ISO basic Latin alphabet. In English, the letter K usually represents the voiceless velar plosive, the letter K comes from the Greek letter Κ, which was taken from the Semitic kap, the symbol for an open hand. This, in turn, was adapted by Semites who had lived in Egypt from the hieroglyph for hand representing D in the Egyptian word for hand. The Semites evidently assigned it the sound value /k/ instead, because their word for hand started with that sound, in the earliest Latin inscriptions, the letters C, K and Q were all used to represent the sounds /k/ and /g/. Of these, Q was used to represent /k/ or /g/ before a vowel, K before /a/. Later, the use of C and its variant G replaced most usages of K and Q, K survived only in a few fossilized forms such as Kalendae, the calends. After Greek words were taken into Latin, the Kappa was transliterated as a C, loanwords from other alphabets with the sound /k/ were also transliterated with C. Hence, the Romance languages generally use C and have K only in loanwords from other language groups. The Celtic languages also tended to use C instead of K, today, English is the only Germanic language to productively use hard ⟨c⟩ rather than ⟨k⟩. The letter ⟨k⟩ is usually silent at the start of an English word when it comes before the letter ⟨n⟩, as in the knight, knife, knot, know. The SI prefix for a thousand is kilo-, officially abbreviated as k—for instance, prefixed to metre or its abbreviation m, kilometre or km signifies a thousand metres. As such, people occasionally represent the number in a notation by replacing the last three zeros of the general numeral with K, for instance, 30K for 30,000. In most languages where it is employed, this represents the sound /k/ or some similar sound. The International Phonetic Alphabet uses ⟨k⟩ for the voiceless velar plosive, K replacing C in Satiric misspelling K is the unit symbol for the Kelvin temperature scale. K is the symbol for the element potassium. Triangle K Unit prefix K is the name of the character in Kafkas novel The Trial In chess notation. In baseball scoring, the letter K is used to represent a strikeout, a forwards oriented K represents a strikeout swinging, a backwards oriented K represents a strikeout looking. As abbreviation for OK, often used in emails and short text messages, K is used as a slang term for Ketamine among recreational drug users