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β (other)
The symbol β, an upward pointing arrow, also called up arrow, uparrow, or upwards arrow, may refer to: Notation * β, a mathematical symbol for "undefined" * β, a notation of Knuth's up-arrow notation for very large integers * β, a mathematical game theory position ''Up'' * β or Sheffer stroke, the logical connective "not both" or NAND * β, the APL function 'take' * "Increased" (and similar meanings), in medical notation * β, a chemical symbol for production of gas, which bubbles up. Character representations * β, upwards arrow, a Unicode arrow symbol * β, ↑, a HTML or XML character entity * β, codepoint 8A (hex) in EBCDIC Code page 293, used for writing APL * β, the glyph for character 94 (decimal) in ASCII until 1967, when it was replaced by the caret (^). See also * κ, an archaic Romanian Cyrillic letter * Arrow keys, on computer keyboards * Arrow (other) ** β (other) ** β (other) β or -> may refer to: * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Undefined (mathematics)
In mathematics, the term undefined is often used to refer to an expression which is not assigned an interpretation or a value (such as an indeterminate form, which has the propensity of assuming different values). The term can take on several different meanings depending on the context. For example: * In various branches of mathematics, certain concepts are introduced as primitive notions (e.g., the terms "point", "line" and "angle" in geometry). As these terms are not defined in terms of other concepts, they may be referred to as "undefined terms". * A function is said to be "undefined" at points outside of its domainfor example, the real-valued function f(x)=\sqrt is undefined for negative x (i.e., it assigns no value to negative arguments). * In algebra, some arithmetic operations may not assign a meaning to certain values of its operands (e.g., division by zero). In which case, the expressions involving such operands are termed "undefined". Undefined terms In ancient tim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Knuth's Up-arrow Notation
In mathematics, Knuth's up-arrow notation is a method of notation for very large integers, introduced by Donald Knuth in 1976. In his 1947 paper, R. L. Goodstein introduced the specific sequence of operations that are now called ''hyperoperations''. Goodstein also suggested the Greek names tetration, pentation, etc., for the extended operations beyond exponentiation. The sequence starts with a unary operation (the successor function with ''n'' = 0), and continues with the binary operations of addition (''n'' = 1), multiplication (''n'' = 2), exponentiation (''n'' = 3), tetration (''n'' = 4), pentation (''n'' = 5), etc. Various notations have been used to represent hyperoperations. One such notation is H_n(a,b). Knuth's up-arrow notation \uparrow is an alternative notation. It is obtained by replacing /math> in the square bracket notation by n-2 arrows. For example: * the single arrow \uparrow represents exponentiation (iterated multiplication) 2 \uparrow 4 = H_3(2,4) = 2\times ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Up (game Theory)
Combinatorial game theory is a branch of mathematics and theoretical computer science that typically studies sequential games with perfect information. Study has been largely confined to two-player games that have a ''position'' that the players take turns changing in defined ways or ''moves'' to achieve a defined winning condition. Combinatorial game theory has not traditionally studied games of chance or those that use imperfect or incomplete information, favoring games that offer perfect information in which the state of the game and the set of available moves is always known by both players. However, as mathematical techniques advance, the types of game that can be mathematically analyzed expands, thus the boundaries of the field are ever changing. Scholars will generally define what they mean by a "game" at the beginning of a paper, and these definitions often vary as they are specific to the game being analyzed and are not meant to represent the entire scope of the field. C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sheffer Stroke
In Boolean functions and propositional calculus, the Sheffer stroke denotes a logical operation that is equivalent to the logical negation, negation of the logical conjunction, conjunction operation, expressed in ordinary language as "not both". It is also called nand ("not and") or the alternative denial, since it says in effect that at least one of its operands is false. In digital electronics, it corresponds to the NAND gate. It is named after Henry M. Sheffer and written as β or as , (but not as , , , often used to represent Logical disjunction, disjunction). In JΓ³zef_Maria_BocheΕski, BocheΕski notation it can be written as D''pq''. Its duality (mathematics), dual is the logical NOR, NOR operator (also known as the Charles Sanders Peirce, Peirce arrow or Willard Van Orman Quine, Quine dagger). Like its dual, NAND can be used by itself, without any other logical operator, to constitute a logical formal system (making NAND functional completeness, functionally complete) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Medical Abbreviations
Abbreviations are used very frequently in medicine. They boost efficiency as long as they are used intelligently. The advantages of brevity should be weighed against the possibilities of obfuscation (making the communication harder for others to understand) and ambiguity (having more than one possible interpretation). Certain medical abbreviations are avoided to prevent mistakes, according to best practices (and in some cases regulatory requirements); these are flagged in the list of abbreviations used in medical prescriptions. Orthographic styling Periods (stops) Periods (stops) are often used in styling abbreviations. Prevalent practice in medicine today is often to forego them as unnecessary. * Example: ** ''Less common:'' The diagnosis was C.O.P.D. hronic obstructive pulmonary disease** ''More common:'' The diagnosis was COPD Plurals The prevalent way to represent plurals for medical acronyms and initialisms is simply to affix a lowercase ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arrow (symbol)
An arrow is a graphical symbol, such as β or β, or a pictogram, used to point or indicate direction. In its simplest form, an arrow is a triangle, chevron, or concave kite, usually affixed to a line segment or rectangle, and in more complex forms a representation of an actual arrow (e.g. β΅ U+27B5). The direction indicated by an arrow is the one along the length of the line or rectangle toward the single pointed end. History An older (medieval) convention is the manicule (pointing hand, π). Pedro Reinel in c. 1504 first used the fleur-de-lis as indicating north in a compass rose; the convention of marking the eastern direction with a cross is older (medieval). Use of the arrow symbol does not appear to pre-date the 18th century. An early arrow symbol is found in an illustration of Bernard Forest de BΓ©lidor's treatise ''L'architecture hydraulique'', printed in France in 1737. The arrow is here used to illustrate the direction of the flow of water and of the wat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of XML And HTML Character Entity References
In SGML, HTML and XML documents, the logical constructs known as ''character data'' and ''attribute values'' consist of sequences of characters, in which each character can manifest directly (representing itself), or can be represented by a series of characters called a ''character reference'', of which there are two types: a ''numeric character reference'' and a ''character entity reference''. This article lists the character entity references that are valid in HTML and XML documents. A character entity reference refers to the content of a named entity. An entity declaration is created by using the syntax in a Document Type Definition (DTD). Character reference overview A numeric character reference refers to a character by its Universal Character Set/Unicode ''code point'', and uses the format: :&#''nnnn''; or :&#x''hhhh''; where ''nnnn'' is the code point in decimal form, and ''hhhh'' is the code point in hexadecimal form. The x must be lowercase in XML documents. The ''nnnn'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Code Page 293
The programming language APL uses a number of symbols, rather than words from natural language, to identify operations, similarly to mathematical symbols. Prior to the wide adoption of Unicode, a number of special-purpose EBCDIC and non-EBCDIC code pages were used to represent the symbols required for writing APL. Character sets Due to its origins on IBM Selectric-based teleprinters, APL symbols have traditionally been represented on the wire using a unique, non-standard character set. In the 1960s and 1970s, few terminal devices existed which could reproduce them, the most popular ones being the IBM 2741 and IBM 1050 fitted with a specific APL print head. Over time, with the universal use of high-quality graphic display, printing devices and Unicode support, the APL character font problem has largely been eliminated. Character repertoire IBM assigns the following character IDs (GCGIDs) to APL syntax, which are used in the definitions of its code pages. EBCDIC code pages Code ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caret
Caret is the name used familiarly for the character , provided on most QWERTY keyboards by typing . The symbol has a variety of uses in programming and mathematics. The name "caret" arose from its visual similarity to the original proofreader's caret, a mark used in proofreading to indicate where a punctuation mark, word, or phrase should be inserted into a document. The formal ASCII standard (X3.64.1977) calls it a "circumflex". History Typewriters On typewriters designed for languages that routinely use diacritics (accent marks), there are two possible ways to type these. Keys can be dedicated to precomposed characters (with the diacritic included) or alternatively a dead key mechanism can be provided. With the latter, a mark is made when a dead key is typed but, unlike normal keys, the paper carriage does not move on and thus the next letter to be typed is printed under the accent. The symbol was originally provided in typewriters and computer printers so that circumfl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arrow Keys
Arrow keys or cursor movement keys are buttons on a computer keyboard that are either programmed or designated to move the cursor (computers), cursor in a specified direction. The term "cursor movement key" is distinct from "arrow key" in that the former term may refer to any of various keys on a computer keyboard designated for cursor movement, whereas "arrow keys" generally refers to one of four specific keys, typically marked with arrows. Arrow keys are typically located at the bottom of the keyboard to the left side of the numeric keypad, usually arranged in an inverted-T layout but also found in diamond shapes and linear shapes. Arrow keys are commonly used for navigating around documents and for playing games. The inverted-T layout was popularized by the Digital Equipment Corporation LK201 keyboard from 1982. Historical development Before the computer mouse was widespread, arrow keys were the primary way of moving a cursor on screen. Mouse keys is a feature that allows ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arrow (other)
An arrow is a projectile launched from a bow. Arrow or arrows may also refer to: Symbols * Arrow (symbol) ** β (other) ** β (other) ** β (other) ** β (other) Places * Arrow, Kentucky * Arrow, Warwickshire, England * Arrow River (New Zealand) * River Arrow, Wales * River Arrow, Worcestershire, England People * Arrow (musician) (1949β2010), calypso and soca musician * Gilbert John Arrow (1873β1948), English entomologist * Kenneth Arrow (1921β2017), American economist, joint winner of the 1972 Nobel Prize in Economics Arts, entertainment, and media Fictional entities * Arrow (comics), a superhero character, first appearing in 1938 * The Arrow, a fictional location, the first Dharma Initiative station in the television series ''Lost'' *Arrow, a character from Rudolph the Red-Nosed Reindeer: The Movie. Music Groups and labels * Arrows (Australian band), indie rock band established 2006 * Arrows (British band), 1970s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
