Multigrade Predicate
In mathematics and logic, plural quantification is the theory that an individual variable x may take on ''plural'', as well as singular, values. As well as substituting individual objects such as Alice, the number 1, the tallest building in London etc. for x, we may substitute both Alice and Bob, or all the numbers between 0 and 10, or all the buildings in London over 20 stories. The point of the theory is to give firstorder logic the power of set theory, but without any " existential commitment" to such objects as sets. The classic expositions are Boolos 1984 and Lewis 1991. History The view is commonly associated with George Boolos, though it is older (see notably Simons 1982), and is related to the view of classes defended by John Stuart Mill and other nominalist philosophers. Mill argued that universals or "classes" are not a peculiar kind of thing, having an objective existence distinct from the individual objects that fall under them, but "is neither more nor less than t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] 

Mathematics
Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represented in modern mathematics with the major subdisciplines of number theory, algebra, geometry, and analysis, respectively. There is no general consensus among mathematicians about a common definition for their academic discipline. Most mathematical activity involves the discovery of properties of abstract objects and the use of pure reason to prove them. These objects consist of either abstractions from nature orin modern mathematicsentities that are stipulated to have certain properties, called axioms. A ''proof'' consists of a succession of applications of deductive rules to already established results. These results include previously proved theorems, axioms, andin case of abstraction from naturesome basic properties that are considered true starting points of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] 

Fred Landman
Fred (Alfred) Landman ( he, פרד לנדמן; born October 28, 1956) is a Dutchborn Israeli professor of semantics. He teaches at Tel Aviv University has written a number of books about linguistics. Biography Fred Landman was born in Holland. He immigrated to Israel in 1993. He was married to Londonborn linguist Susan Rothstein until her death in 2019. The couple had one daughter and resided in Tel Aviv. Academic career Landman is known for his work on progressives, polarity phenomena, groups, and other topics in semantics and pragmatics. He taught at Brown University and Cornell University Cornell University is a private statutory landgrant research university based in Ithaca, New York. It is a member of the Ivy League. Founded in 1865 by Ezra Cornell and Andrew Dickson White, Cornell was founded with the intention to tea ... before moving to Israel. Published works * ''Indefinites and the Type of Sets'' (2004) * ''Events and Plurality: The Jerusalem Lectures'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] 

Paradox
A paradox is a logically selfcontradictory statement or a statement that runs contrary to one's expectation. It is a statement that, despite apparently valid reasoning from true premises, leads to a seemingly selfcontradictory or a logically unacceptable conclusion. A paradox usually involves contradictoryyetinterrelated elements that exist simultaneously and persist over time. They result in "persistent contradiction between interdependent elements" leading to a lasting "unity of opposites". In logic, many paradoxes exist that are known to be invalid arguments, yet are nevertheless valuable in promoting critical thinking, while other paradoxes have revealed errors in definitions that were assumed to be rigorous, and have caused axioms of mathematics and logic to be reexamined. One example is Russell's paradox, which questions whether a "list of all lists that do not contain themselves" would include itself, and showed that attempts to found set theory on the identification ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] 

Foundations Of Mathematics
Foundations of mathematics is the study of the philosophy, philosophical and logical and/or algorithmic basis of mathematics, or, in a broader sense, the mathematical investigation of what underlies the philosophical theories concerning the nature of mathematics. In this latter sense, the distinction between foundations of mathematics and philosophy of mathematics turns out to be quite vague. Foundations of mathematics can be conceived as the study of the basic mathematical concepts (set, function, geometrical figure, number, etc.) and how they form hierarchies of more complex structures and concepts, especially the fundamentally important structures that form the language of mathematics (formulas, theories and their model theory, models giving a meaning to formulas, definitions, proofs, algorithms, etc.) also called metamathematics, metamathematical concepts, with an eye to the philosophical aspects and the unity of mathematics. The search for foundations of mathematics is a cent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] 

Monadic Logic
In logic, the monadic predicate calculus (also called monadic firstorder logic) is the fragment of firstorder logic in which all relation symbols in the signature are monadic (that is, they take only one argument), and there are no function symbols. All atomic formulas are thus of the form P(x), where P is a relation symbol and x is a variable. Monadic predicate calculus can be contrasted with polyadic predicate calculus, which allows relation symbols that take two or more arguments. Expressiveness The absence of polyadic relation symbols severely restricts what can be expressed in the monadic predicate calculus. It is so weak that, unlike the full predicate calculus, it is decidable—there is a decision procedure that determines whether a given formula of monadic predicate calculus is logically valid (true for all nonempty domains). Löwenheim, L. (1915) "Über Möglichkeiten im Relativkalkül," ''Mathematische Annalen'' 76: 447470. Translated as "On possibilities in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] 

Secondorder Logic
In logic and mathematics, secondorder logic is an extension of firstorder logic, which itself is an extension of propositional logic. Secondorder logic is in turn extended by higherorder logic and type theory. Firstorder logic quantifies only variables that range over individuals (elements of the domain of discourse); secondorder logic, in addition, also quantifies over relations. For example, the secondorder sentence \forall P\,\forall x (Px \lor \neg Px) says that for every formula ''P'', and every individual ''x'', either ''Px'' is true or not(''Px'') is true (this is the law of excluded middle). Secondorder logic also includes quantification over sets, functions, and other variables (see section below). Both firstorder and secondorder logic use the idea of a domain of discourse (often called simply the "domain" or the "universe"). The domain is a set over which individual elements may be quantified. Examples Firstorder logic can quantify over individuals, bu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] 

Nonfirstorderizable
In formal logic, nonfirstorderizability is the inability of a naturallanguage statement to be adequately captured by a formula of firstorder logic. Specifically, a statement is nonfirstorderizable if there is no formula of firstorder logic which is true in a model if and only if the statement holds in that model. Nonfirstorderizable statements are sometimes presented as evidence that firstorder logic is not adequate to capture the nuances of meaning in natural language. The term was coined by George Boolos in his paper "To Be is to Be a Value of a Variable (or to Be Some Values of Some Variables)". Reprinted in Quine argued that such sentences call for secondorder symbolization, which can be interpreted as plural quantification over the same domain as firstorder quantifiers use, without postulation of distinct "secondorder objects" (properties, sets, etc.). Examples GeachKaplan sentence A standard example is the '' Geach– Kaplan sentence'': "Some critics admire onl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] 

Geach–Kaplan Sentence
In formal logic, nonfirstorderizability is the inability of a naturallanguage statement to be adequately captured by a formula of firstorder logic. Specifically, a statement is nonfirstorderizable if there is no formula of firstorder logic which is true in a model if and only if the statement holds in that model. Nonfirstorderizable statements are sometimes presented as evidence that firstorder logic is not adequate to capture the nuances of meaning in natural language. The term was coined by George Boolos in his paper "To Be is to Be a Value of a Variable (or to Be Some Values of Some Variables)". Reprinted in Quine argued that such sentences call for secondorder symbolization, which can be interpreted as plural quantification over the same domain as firstorder quantifiers use, without postulation of distinct "secondorder objects" (properties, sets, etc.). Examples GeachKaplan sentence A standard example is the '' Geach– Kaplan sentence'': "Some critics admire onl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] 

Abstract Entity
In metaphysics, the distinction between abstract and concrete refers to a divide between two types of entities. Many philosophers hold that this difference has fundamental metaphysical significance. Examples of concrete objects include plants, human beings and planets while things like numbers, sets and propositions are abstract objects. There is no general consensus as to what the characteristic marks of concreteness and abstractness are. Popular suggestions include defining the distinction in terms of the difference between (1) existence inside or outside spacetime, (2) having causes and effects or not, (3) having contingent or necessary existence, (4) being particular or universal and (5) belonging to either the physical or the mental realm or to neither. Despite this diversity of views, there is broad agreement concerning most objects as to whether they are abstract or concrete. So under most interpretations, all these views would agree that, for example, plants are concrete ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] 

Problem Of Universals
The problem of universals is an ancient question from metaphysics that has inspired a range of philosophical topics and disputes: Should the properties an object has in common with other objects, such as color and shape, be considered to exist beyond those objects? And if a property exists separately from objects, what is the nature of that existence? The problem of universals relates to various inquiries closely related to metaphysics, logic, and epistemology, as far back as Plato and Aristotle, in efforts to define the mental connections a human makes when they understand a property such as shape or color to be the same in nonidentical objects. Universals are qualities or relations found in two or more entities. As an example, if all cup holders are ''circular'' in some way, ''circularity'' may be considered a universal property of cup holders. Further, if two daughters can be considered ''female offspring of Frank'', the qualities of being ''female'', ''offspring'', and ''of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] 

Willard Van Orman Quine
Willard Van Orman Quine (; known to his friends as "Van"; June 25, 1908 – December 25, 2000) was an American philosopher and logician in the analytic tradition, recognized as "one of the most influential philosophers of the twentieth century". From 1930 until his death 70 years later, Quine was continually affiliated with Harvard University in one way or another, first as a student, then as a professor. He filled the Edgar Pierce Chair of Philosophy at Harvard from 1956 to 1978. Quine was a teacher of logic and set theory. Quine was famous for his position that first order logic is the only kind worthy of the name, and developed his own system of mathematics and set theory, known as New Foundations. In philosophy of mathematics, he and his Harvard colleague Hilary Putnam developed the Quine–Putnam indispensability argument, an argument for the reality of mathematical entities.Colyvan, Mark"Indispensability Arguments in the Philosophy of Mathematics" The Stanford Encyclopedi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] 

Arity
Arity () is the number of arguments or operands taken by a function, operation or relation in logic, mathematics, and computer science. In mathematics, arity may also be named ''rank'', but this word can have many other meanings in mathematics. In logic and philosophy, it is also called adicity and degree. In linguistics, it is usually named valency. Examples The term "arity" is rarely employed in everyday usage. For example, rather than saying "the arity of the addition operation is 2" or "addition is an operation of arity 2" one usually says "addition is a binary operation". In general, the naming of functions or operators with a given arity follows a convention similar to the one used for ''n''based numeral systems such as binary and hexadecimal. One combines a Latin prefix with the ary ending; for example: * A nullary function takes no arguments. ** Example: f()=2 * A unary function takes one argument. ** Example: f(x)=2x * A binary function takes two arguments. ** Examp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] 