Bijective numeration is any numeral system in which every non-negative integer can be represented in exactly one way using a finite string of digits . The name refers to the bijection (i.e. one-to-one correspondence) that exists in this case between the set of non-negative integers and the set of finite strings using a finite set of symbols (the "digits").
30-406: The ISO basic Latin alphabet is an international standard (beginning with ISO/IEC 646) for a Latin-script alphabet that consists of two sets ( uppercase and lowercase) of 26 letters, codified in various national and international standards and used widely in international communication . They are the same letters that comprise the current English alphabet . Since medieval times, they are also
60-525: A digit's position in the string defines its value as a multiple of a power of k . Smullyan (1961) calls this notation k -adic, but it should not be confused with the p -adic numbers : bijective numerals are a system for representing ordinary integers by finite strings of nonzero digits, whereas the p -adic numbers are a system of mathematical values that contain the integers as a subset and may need infinite sequences of digits in any numerical representation. The base- k bijective numeration system uses
90-500: A ligature of ⟨ſ⟩ ( long s ) and ⟨s⟩ ), but the current German orthographic rules include ⟨ä⟩ , ⟨ö⟩ , ⟨ü⟩ , ⟨ß⟩ in the alphabet placed after ⟨Z⟩ . In Spanish orthography, the letters ⟨n⟩ and ⟨ñ⟩ are distinct; the tilde is not considered a diacritic in this case. Trigraphs : ⟨aai⟩, ⟨eeu⟩, ⟨oei⟩, ⟨ooi⟩ * Constructed languages The Roman (Latin) alphabet
120-457: Is a " folk theorem " that has been rediscovered many times. Early instances are Foster (1947) for the case k = 10, and Smullyan (1961) and Böhm (1964) for all k ≥ 1. Smullyan uses this system to provide a Gödel numbering of the strings of symbols in a logical system; Böhm uses these representations to perform computations in the programming language P′′ . Knuth (1969) mentions the special case of k = 10, and Salomaa (1973) discusses
150-412: Is a base ten positional numeral system that does not use a digit to represent zero . It instead has a digit to represent ten, such as A . As with conventional decimal , each digit position represents a power of ten, so for example 123 is "one hundred, plus two tens, plus three units." All positive integers that are represented solely with non-zero digits in conventional decimal (such as 123) have
180-1154: Is because the Euler summation meaning that and for every positive number n {\displaystyle n} with bijective numeration digit representation d {\displaystyle d} is represented by d k − 1 ¯ d k d {\displaystyle {\overline {d_{k-1}}}d_{k}d} . For base k > 2 {\displaystyle k>2} , negative numbers n < − 1 {\displaystyle n<-1} are represented by d k − 1 ¯ d i d {\displaystyle {\overline {d_{k-1}}}d_{i}d} with i < k − 1 {\displaystyle i<k-1} , while for base k = 2 {\displaystyle k=2} , negative numbers n < − 1 {\displaystyle n<-1} are represented by d k ¯ d {\displaystyle {\overline {d_{k}}}d} . This
210-431: Is commonly used for column numbering in a table or chart. This avoids confusion with row numbers using Arabic numerals . For example, a 3-by-3 table would contain columns A, B, and C, set against rows 1, 2, and 3. If more columns are needed beyond Z (normally the final letter of the alphabet), the column immediately after Z is AA, followed by AB, and so on (see bijective base-26 system ). This can be seen by scrolling far to
240-418: Is no longer bijective, as the entire set of left-infinite sequences of digits is used to represent the k {\displaystyle k} -adic integers , of which the integers are only a subset. For a given base k ≥ 2 {\displaystyle k\geq 2} , For a given base k ≥ 1 {\displaystyle k\geq 1} , The bijective base-10 system
270-427: Is similar to how in signed-digit representations , all integers n {\displaystyle n} with digit representations d {\displaystyle d} are represented as d 0 ¯ d {\displaystyle {\overline {d_{0}}}d} where f ( d 0 ) = 0 {\displaystyle f(d_{0})=0} . This representation
300-665: The Latin script in their ( ISO/IEC 646 ) 7-bit character-encoding standard. To achieve widespread acceptance, this encapsulation was based on popular usage. The standard was based on the already published American Standard Code for Information Interchange , better known as ASCII , which included in the character set the 26 × 2 letters of the English alphabet . Later standards issued by the ISO, for example ISO/IEC 8859 (8-bit character encoding) and ISO/IEC 10646 ( Unicode Latin ), have continued to define
330-402: The 23-letter classical Latin alphabet belong to the oldest of this group. The 26-letter modern Latin alphabet is the newest of this group. The 26-letter ISO basic Latin alphabet (adopted from the earlier ASCII ) contains the 26 letters of the English alphabet . To handle the many other alphabets also derived from the classical Latin one, ISO and other telecommunications groups "extended"
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#1733094019649360-583: The 26 × 2 letters of the English alphabet as the basic Latin script with extensions to handle other letters in other languages. The Unicode block that contains the alphabet is called " C0 Controls and Basic Latin ". Two subheadings exist: There are also another two sets in the Halfwidth and Fullwidth Forms block: In ASCII the letters belong to the printable characters and in Unicode since version 1.0 they belong to
390-553: The French é and the German ö are not listed separately in their respective alphabet sequences. With some alphabets, some altered letters are considered distinct while others are not; for instance, in Spanish, ñ (which indicates a unique phoneme) is listed separately, while á, é, í, ó, ú, and ü (which do not; the first five of these indicate a nonstandard stress-accent placement, while the last forces
420-500: The ISO basic Latin multiple times in the late 20th century. More recent international standards (e.g. Unicode ) include those that achieved ISO adoption. Apart from alphabets for modern spoken languages, there exist phonetic alphabets and spelling alphabets in use derived from Latin script letters. Historical languages may also have used (or are now studied using) alphabets that are derived but still distinct from those of classical Latin and their modern forms (if any). The Latin script
450-653: The block " C0 Controls and Basic Latin ". In both cases, as well as in ISO/IEC 646 , ISO/IEC 8859 and ISO/IEC 10646 they are occupying the positions in hexadecimal notation 41 to 5A for uppercase and 61 to 7A for lowercase. Not case sensitive, all letters have code words in the ICAO spelling alphabet and can be represented with Morse code . All of the lowercase letters are used in the International Phonetic Alphabet (IPA). In X-SAMPA and SAMPA these letters have
480-454: The conventional 1402. In the bijective base-26 system one may use the Latin alphabet letters "A" to "Z" to represent the 26 digit values one to twenty-six . (A=1, B=2, C=3, ..., Z=26) With this choice of notation, the number sequence (starting from 1) begins A, B, C, ..., X, Y, Z, AA, AB, AC, ..., AX, AY, AZ, BA, BB, BC, ... Each digit position represents a power of twenty-six, so for example,
510-406: The digit-set {1, 2, ..., k } ( k ≥ 1) to uniquely represent every non-negative integer, as follows: In contrast, standard positional notation can be defined with a similar recursive algorithm where For base k > 1 {\displaystyle k>1} , the bijective base- k {\displaystyle k} numeration system could be extended to negative integers in
540-480: The end, as well as one letter with diacritic, while others with diacritics are sorted behind the corresponding non-diacritic letter. The phonetic values of graphemes can differ between alphabets. Bijective numeration#The bijective base-26 system Most ordinary numeral systems, such as the common decimal system, are not bijective because more than one string of digits can represent the same positive integer. In particular, adding leading zeroes does not change
570-451: The first widespread Microsoft Word macro virus, Concept, is formally named WM/Concept.A, its 26th variant WM/Concept.Z, the 27th variant WM/Concept.AA, et seq. A variant of this system is used to name variable stars . It can be applied to any problem where a systematic naming using letters is desired, while using the shortest possible strings. The fact that every non-negative integer has a unique representation in bijective base- k ( k ≥ 1)
600-477: The numeral WI represents the value 23 × 26 + 9 × 26 = 607 in base 10. Many spreadsheets including Microsoft Excel use this system to assign labels to the columns of a spreadsheet, starting A, B, C, ..., Z, AA, AB, ..., AZ, BA, ..., ZZ, AAA, etc. For instance, in Excel 2013, there can be up to 16384 columns (2 in binary code), labeled from A to XFD. Malware variants are also named using this system: for example,
630-455: The pronunciation of a normally-silent letter) are not. Digraphs in some languages may be separately included in the collation sequence (e.g. Hungarian CS, Welsh RH). New letters must be separately included unless collation is not practised. Coverage of the letters of the ISO basic Latin alphabet can be and additional letters can be Most alphabets have the letters of the ISO basic Latin alphabet in
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#1733094019649660-446: The right in a spreadsheet program such as Microsoft Excel or LibreOffice Calc . The letters are often used for indexing nested bullet points. In this case after the 26th it is more common to use AA, BB, CC, ... instead of base-26 numbers. Latin-script alphabet A Latin-script alphabet ( Latin alphabet or Roman alphabet ) is an alphabet that uses letters of the Latin script . The 21-letter archaic Latin alphabet and
690-406: The same as with conventional decimal, except that carries occur when a position exceeds ten, rather than when it exceeds nine. So to calculate 643 + 759, there are twelve units (write 2 at the right and carry 1 to the tens), ten tens (write A with no need to carry to the hundreds), thirteen hundreds (write 3 and carry 1 to the thousands), and one thousand (write 1), to give the result 13A2 rather than
720-474: The same letters of the modern Latin alphabet . The order is also important for sorting words into alphabetical order . The two sets contain the following 26 letters each: By the 1960s it became apparent to the computer and telecommunications industries in the First World that a non-proprietary method of encoding characters was needed. The International Organization for Standardization (ISO) encapsulated
750-523: The same order as that alphabet. Some alphabets regard digraphs as distinct letters, e.g. the Spanish alphabet from 1803 to 1994 had CH and LL sorted apart from C and L. Some alphabets sort letters that have diacritics or are ligatures at the end of the alphabet. Examples are the Scandinavian Danish , Norwegian , Swedish , and Finnish alphabets. Icelandic sorts a new letter form and a ligature at
780-412: The same representation in the bijective base-10 system. Those that use a zero must be rewritten, so for example 10 becomes A, conventional 20 becomes 1A, conventional 100 becomes 9A, conventional 101 becomes A1, conventional 302 becomes 2A2, conventional 1000 becomes 99A, conventional 1110 becomes AAA, conventional 2010 becomes 19AA, and so on. Addition and multiplication in this system are essentially
810-466: The same sound value as in IPA. The list below only includes alphabets that include all the 26 letters but exclude: Notable omissions due to these rules include Spanish , Esperanto , Filipino and German . The German alphabet is sometimes considered by tradition to contain only 26 letters (with ⟨ä⟩ , ⟨ö⟩ , ⟨ü⟩ considered variants and ⟨ß⟩ considered
840-690: The same way as the standard base- b {\displaystyle b} numeral system by use of an infinite number of the digit d k − 1 {\displaystyle d_{k-1}} , where f ( d k − 1 ) = k − 1 {\displaystyle f(d_{k-1})=k-1} , represented as a left-infinite sequence of digits … d k − 1 d k − 1 d k − 1 = d k − 1 ¯ {\displaystyle \ldots d_{k-1}d_{k-1}d_{k-1}={\overline {d_{k-1}}}} . This
870-456: The value represented, so "1", "01" and "001" all represent the number one . Even though only the first is usual, the fact that the others are possible means that the decimal system is not bijective. However, the unary numeral system , with only one digit, is bijective. A bijective base - k numeration is a bijective positional notation . It uses a string of digits from the set {1, 2, ..., k } (where k ≥ 1) to encode each positive integer;
900-485: Was typically slightly altered to function as an alphabet for each different language (or other use), although the main letters are largely the same. A few general classes of alteration cover many particular cases: These often were given a place in the alphabet by defining an alphabetical order or collation sequence, which can vary between languages. Some of the results, especially from just adding diacritics, were not considered distinct letters for this purpose; for example,
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