Please answer the following question: Information:  - Philosophy of language seeks to understand the relationship between language and reality. Major topics in philosophy of language are the nature of meaning, intentionality, reference, the constitution of sentences, learning, and thought.  - Ludwig Josef Johann Wittgenstein (26 April 1889  29 April 1951) was an Austrian-British philosopher who worked primarily in logic, the philosophy of mathematics, the philosophy of mind, and the philosophy of language. From 1929 to 1947, Wittgenstein taught at the University of Cambridge. During his lifetime he published just one slim book, the 75-page "Tractatus Logico-Philosophicus" (1921), one article, one book review and a children's dictionary. His voluminous manuscripts were edited and published posthumously. "Philosophical Investigations" appeared as a book in 1953, and has since come to be recognised as one of the most important works of philosophy in the twentieth century. His teacher Bertrand Russell described Wittgenstein as "the most perfect example I have ever known of genius as traditionally conceived; passionate, profound, intense, and dominating."  - A ring name is a stage name used by a professional wrestler, martial artist, or a boxer. While some ring names may have a fictitious first name and surname, others may simply be a nickname from the moves that they do or their talents in the ring.  - The University of WisconsinMadison (also known as University of Wisconsin, Wisconsin, UW, or regionally as UWMadison, or simply Madison) is a public research university in Madison, Wisconsin, United States. Founded when Wisconsin achieved statehood in 1848, UWMadison is the official state university of Wisconsin, and the flagship campus of the University of Wisconsin System. It was the first public university established in Wisconsin and remains the oldest and largest public university in the state. It became a land-grant institution in 1866. The main campus includes four National Historic Landmarks.  - In academia, a Festschrift (plural, "Festschriften" ) is a book honoring a respected person, especially an academic, and presented during his or her lifetime. The term, borrowed from German, could be translated as "celebration publication" or "celebratory (piece of) writing" (literally 'party-writing'; cognate with 'feast-script'). A comparable book presented posthumously is called a Gedenkschrift ("memorial publication"). Sometimes, the Latin term liber amicorum (literally: book of friends) is used for a Festschrift. The German word "Festschrift" has been incorporated into the English language.  - Martin Stokhof (born 1950, Amsterdam) is a Dutch logician and philosopher. Stokhof wrote a joint Ph.D. dissertation with Jeroen Groenendijk on the semantics of questions, under the supervision of Renate Bartsch and Johan van Benthem. He was also an important figure in the development of dynamic semantics (together with Groenendijk, Veltman and others). He is also known for his work on Ludwig Wittgenstein.  - Intuitionistic logic, sometimes more generally called constructive logic, is a system of symbolic logic that differs from classical logic by replacing the traditional concept of truth with the concept of constructive provability. For example, in classical logic, propositional formulae are always assigned a truth value from the two-element set of trivial propositions formula_1 ("true" and "false" respectively) regardless of whether we have direct evidence for either case. This is referred to as the 'law of excluded middle', because it excludes the possibility of any truth value besides 'true' or 'false'. In contrast, propositional formulae in intuitionistic logic are "not" assigned any definite truth value at all and instead "only" considered "true" when we have direct evidence, hence "proof". (We can also say, instead of the propositional formula being "true" due to direct evidence, that it is inhabited by a proof in the CurryHoward sense.) Operations in intuitionistic logic therefore preserve justification, with respect to evidence and provability, rather than truth-valuation.  - L. T. F. Gamut was a collective pseudonym for the Dutch logicians Johan van Benthem , Jeroen Groenendijk , Dick de Jongh , Martin Stokhof and Henk Verkuyl . Gamut stands for the Dutch universities of Groningen ( G ) , Amsterdam ( am ) , and Utrecht ( ut ) , then the affiliations of the authors . The initials L. T. F. stand for the discussed topics , respectively , Logic ( Dutch : Logica ) , Language ( Dutch : Taal ) and Philosophy ( Dutch : Filosofie ) .  - Pragmatics is a subfield of linguistics and semiotics that studies the ways in which context contributes to meaning. Pragmatics encompasses speech act theory, conversational implicature, talk in interaction and other approaches to language behavior in philosophy, sociology, linguistics and anthropology. Unlike semantics, which examines meaning that is conventional or "coded" in a given language, pragmatics studies how the transmission of meaning depends not only on structural and linguistic knowledge (e.g., grammar, lexicon, etc.) of the speaker and listener, but also on the context of the utterance, any pre-existing knowledge about those involved, the inferred intent of the speaker, and other factors. In this respect, pragmatics explains how language users are able to overcome apparent ambiguity, since meaning relies on the manner, place, time etc. of an utterance.  - A pseudonym (and ) or alias is a name that a person or group assumes for a particular purpose, which can differ from their original or true name (orthonym). Pseudonyms include stage names and user names (both called "screen names"), ring names, pen names, nicknames, aliases, superhero identities and code names, gamer identifications, and regnal names of emperors, popes, and other monarchs. Historically, they have often taken the form of anagrams, Graecisms, and Latinisations, although there are many other methods of choosing a pseudonym.  - Proof theory is a major branch of mathematical logic that represents proofs as formal mathematical objects, facilitating their analysis by mathematical techniques. Proofs are typically presented as inductively-defined data structures such as plain lists, boxed lists, or trees, which are constructed according to the axioms and rules of inference of the logical system. As such, proof theory is syntactic in nature, in contrast to model theory, which is semantic in nature.  - In modern popular fiction, a superhero (sometimes rendered super-hero or super hero) is a type of costumed heroic character who possesses supernatural or superhuman powers and who is dedicated to fighting crime, protecting the public, and usually battling supervillains. A female superhero is sometimes called a superheroine (also rendered super-heroine or super heroine). Fiction centered on such characters, especially in American comic books since the 1930s, is known as superhero fiction.  - A name is a term used for identification. Names can identify a class or category of things, or a single thing, either uniquely, or within a given context. A personal name identifies, not necessarily uniquely, a "specific" individual human. The name of a specific entity is sometimes called a proper name (although that term has a philosophical meaning also) and is, when consisting of only one word, a proper noun. Other nouns are sometimes called "common names" or (obsolete) "general names". A name can be given to a person, place, or thing; for example, parents can give their child a name or a scientist can give an element a name.  - Semantics (from "smantikos", "significant") is primarily the linguistic, and also philosophical study of meaningin language, programming languages, formal logics, and semiotics. It focuses on the relationship between "signifiers"like words, phrases, signs, and symbolsand what they stand for, their denotation.  - Dick Herman Jacobus de Jongh (born 19 October 1939, Enschede) is a Dutch logician and mathematician and a retired professor at the University of Amsterdam. He received his PhD degree in 1968 from the University of WisconsinMadison under supervision of Stephen Kleene with a dissertation entitled "Investigations on the Intuitionistic Propositional Calculus". De Jongh is mostly known for his work on proof theory, provability logic and intuitionistic logic. De Jongh is a member of the group collectively publishing under the pseudonym L. T. F. Gamut. In 2004, on the occasion of his retirement, the Institute for Logic, Language and Computation at the University of Amsterdam published a festschrift in his honor.  - Jeroen Antonius Gerardus Groenendijk (born 20 July 1949, Amsterdam), is a Dutch logician, linguist and philosopher, working on philosophy of language, formal semantics, pragmatics.  - A pen name ("nom de plume", or "literary double") is a pseudonym (or, in some cases, a variant form of a real name) adopted by an author and printed on the title page or by-line of his or her works in place of their "real" name. A pen name may be used to make the author's name more distinctive, to disguise his or her gender, to distance an author from some or all of his or her previous works, to protect the author from retribution for his or her writings, to combine more than one author into a single author, or for any of a number of reasons related to the marketing or aesthetic presentation of the work. The author's name may be known only to the publisher, or may come to be common knowledge.  - Provability logic is a modal logic, in which the box (or "necessity") operator is interpreted as 'it is provable that'. The point is to capture the notion of a proof predicate of a reasonably rich formal theory, such as Peano arithmetic.     What object entity has the relation of 'field of work' with the subject 'l. t. f. gamut'?   Choices: - anthropology  - artist  - author  - class  - comic  - english  - fiction  - language  - law  - linguist  - linguistics  - logic  - ludwig wittgenstein  - marketing  - mathematical logic  - mathematician  - philosopher  - philosophy  - philosophy of language  - philosophy of mind  - proof theory  - research  - sociology  - writing
Answer:
mathematical logic