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Peirce's Law
In logic, Peirce's law is named after the philosopher and logician Charles Sanders Peirce. It was taken as an Axiom#Mathematics, axiom in his first axiomatisation of propositional logic. It can be thought of as the law of excluded middle written in a form that involves only one sort of connective, namely implication. In propositional calculus, Peirce's law says that ((''P''→''Q'')→''P'')→''P''. Written out, this means that ''P'' must be true if there is a proposition ''Q'' such that the truth of ''P'' Logical consequence, follows from the truth of "if ''P'' then ''Q''". Peirce's law does not hold in intuitionistic logic or intermediate logics and cannot be deduced from the deduction theorem alone. Under the Curry–Howard isomorphism, Peirce's law is the type of continuation operators, e.g. call/cc in Scheme (programming language), Scheme. v \end \end and where Peirce's law as a formula can be simplified to: : \begin ((u \mathrel v) \ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Logic
Logic is the study of correct reasoning. It includes both formal and informal logic. Formal logic is the study of deductively valid inferences or logical truths. It examines how conclusions follow from premises based on the structure of arguments alone, independent of their topic and content. Informal logic is associated with informal fallacies, critical thinking, and argumentation theory. Informal logic examines arguments expressed in natural language whereas formal logic uses formal language. When used as a countable noun, the term "a logic" refers to a specific logical formal system that articulates a proof system. Logic plays a central role in many fields, such as philosophy, mathematics, computer science, and linguistics. Logic studies arguments, which consist of a set of premises that leads to a conclusion. An example is the argument from the premises "it's Sunday" and "if it's Sunday then I don't have to work" leading to the conclusion "I don't have to wor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Second-order Propositional Logic
A second-order propositional logic is a propositional logic extended with quantification over propositions. A special case are the logics that allow second-order Boolean propositions, where quantifiers may range either just over the Boolean truth values, or over the Boolean-valued truth functions. The most widely known formalism is the intuitionistic logic with impredicative quantification, System F. showed how this calculus can be extended to admit classical logic. See also *True quantified Boolean formula *Second-order arithmetic *Second-order logic *Type theory In mathematics and theoretical computer science, a type theory is the formal presentation of a specific type system. Type theory is the academic study of type systems. Some type theories serve as alternatives to set theory as a foundation of ... References * {{logic-stub Propositional calculus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthur W
The Countess (French language, French: ''La Comtesse''; born Arthur Berloget), also known as Pauline and Arthur W, was a French transgender courtesan, demimondaine, singer, artist, and writer who was prominent in Parisian society throughout the 1850s and 1860s. She was the mistress of a French nobility, nobleman and later became a singer in Parisian cafés and cabarets. Berloget was an active member of an LGBT community in Paris, whose members were called ''filles'', ''mignons'' and ''tribade sisters''. She was drafted to serve in the French Army, and was forced to temporarily de-transition. She was arrested in 1861 for robbery and for desertion, deserting her post, and was sentenced to ten years in prison. In 1874, she authored an autobiography ''The Secret Confessions of a Parisian: The Countess, 1850-1871'', which was published in 1895. Her autobiography describes intimate details of her life living as a woman during the Second French Empire and the beginning of Belle Époque ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paul Weiss (philosopher)
Paul Weiss (; May 19, 1901 – July 5, 2002) was an American philosopher. He was the founder of '' The Review of Metaphysics'' and the Metaphysical Society of America. Early life and education Paul Weiss grew up on the Lower East Side of New York City. His father, Samuel Weiss (d. 1917), was a Jewish emigrant who moved from Europe in the 1890s. He worked as a tinsmith, a coppersmith, and a boilermaker. Paul Weiss's mother, Emma Rothschild (Weiss) (d. 1915), was a Jewish emigrant who worked as a servant until she married Samuel. Born into a Jewish family, Paul lived among other Jewish families in a working-class neighborhood in the Yorkville section of Manhattan. Originally given the Hebrew name "Peretz," Weiss says in his autobiography that the name "Paul" was his "registered name" and "part of his mother's attempt to move upward in the American world."Weiss, Paul. The Philosophy of Paul Weiss. Ed. Lewis Hahn. Chicago : Open Court, 1995. He had three brothers, two older and one ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charles Hartshorne
Charles Hartshorne (; June 5, 1897 – October 9, 2000) was an American philosopher who concentrated primarily on the philosophy of religion and metaphysics, but also contributed to ornithology. He developed the neoclassical idea of God and produced a modal proof of the existence of God that was a development of Anselm of Canterbury's ontological argument. Hartshorne is also noted for developing Alfred North Whitehead's process philosophy into process theology. Early life and education Hartshorne was born in Kittanning, Pennsylvania, and was a son of the Reverend Francis Cope Hartshorne (1868–1950) and Marguerite Haughton (1868–1959), who were married on April 25, 1895, in Bryn Mawr, Montgomery County, Pennsylvania. the Rev. F. C. Hartshorne, who was a minister in the Protestant Episcopal Church, was rector of St. Paul's Episcopal Church in Kittanning from 1897 to 1909, then rector of St. Peter's Episcopal Church in Phoenixville, Pennsylvania, for 19 years (from 19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charles Sanders Peirce Bibliography
This Charles Sanders Peirce bibliography consolidates numerous references to the writings of Charles Sanders Peirce, including letters, manuscripts, publications, and . For an extensive chronological list of Peirce's works (titled in English), see the (Chronological Overview) on the (Writings) page for Charles Sanders Peirce. Abbreviations Click on abbreviation in order to jump down this page to the relevant edition information. Click on the abbreviation appearing with that edition information in order to return here. Main editions (posthumous) Other Primary literature Bibliographies and microfilms Other bibliographies of primary literature * Burks, Arthur W. (1958). "Bibliography of the Works of Charles Sanders Peirce." CP 8:260–321. * Cohen, Morris R. (1916). "Charles S. Peirce and a Tentative Bibliography of His Published Writings." '' The Journal of Philosophy, Psychology, and Scientific Methods'' 13(26):726–37. *Fisch, Max H. (1964). "A First Supplement ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fuzzy Logic
Fuzzy logic is a form of many-valued logic in which the truth value of variables may be any real number between 0 and 1. It is employed to handle the concept of partial truth, where the truth value may range between completely true and completely false. By contrast, in Boolean algebra, Boolean logic, the truth values of variables may only be the integer values 0 or 1. The term ''fuzzy logic'' was introduced with the 1965 proposal of fuzzy set theory by mathematician Lotfi A. Zadeh, Lotfi Zadeh. Fuzzy logic had, however, been studied since the 1920s, as Łukasiewicz logic, infinite-valued logic—notably by Jan Łukasiewicz, Łukasiewicz and Alfred Tarski, Tarski. Fuzzy logic is based on the observation that people make decisions based on imprecise and non-numerical information. Fuzzy models or fuzzy sets are mathematical means of representing vagueness and imprecise information (hence the term fuzzy). These models have the capability of recognising, representing, manipulating, in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Many-valued Logic
Many-valued logic (also multi- or multiple-valued logic) is a propositional calculus in which there are more than two truth values. Traditionally, in Aristotle's Term logic, logical calculus, there were only two possible values (i.e., "true" and "false") for any proposition. Classical two-valued logic may be extended to ''n''-valued logic for ''n'' greater than 2. Those most popular in the literature are Three-valued logic, three-valued (e.g., Jan Łukasiewicz, Łukasiewicz's and Stephen Cole Kleene, Kleene's, which accept the values "true", "false", and "unknown"), four-valued logic, four-valued, nine-valued logic, nine-valued, the finite-valued logic, finite-valued (finitely-many valued) with more than three values, and the infinite-valued logic, infinite-valued (infinitely-many-valued), such as fuzzy logic and probabilistic logic, probability logic. History It is ''wrong'' that the first known classical logician who did not fully accept the law of excluded middle was Aristotle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intermediate Logic
In mathematical logic, a superintuitionistic logic is a propositional logic extending intuitionistic logic. Classical logic is the strongest consistent superintuitionistic logic; thus, consistent superintuitionistic logics are called intermediate logics (the logics are intermediate between intuitionistic logic and classical logic).. Definition A superintuitionistic logic is a set ''L'' of propositional formulas in a countable set of variables ''p''''i'' satisfying the following properties: :1. all axioms of intuitionistic logic belong to ''L''; :2. if ''F'' and ''G'' are formulas such that ''F'' and ''F'' → ''G'' both belong to ''L'', then ''G'' also belongs to ''L'' (closure under modus ponens); :3. if ''F''(''p''1, ''p''2, ..., ''p''''n'') is a formula of ''L'', and ''G''1, ''G''2, ..., ''G''''n'' are any formulas, then ''F''(''G''1, ''G''2, ..., ''G''''n'') belongs to ''L'' (closure under substitution). Such a logic is intermediate if furthermore :4. ''L'' is not the set of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disjunctive Syllogism
In classical logic, disjunctive syllogism (historically known as ''modus tollendo ponens'' (MTP), Latin for "mode that affirms by denying") is a valid argument form which is a syllogism having a disjunctive statement for one of its premises. An example in English: # I will choose soup or I will choose salad. # I will not choose soup. # Therefore, I will choose salad. Propositional logic In propositional logic, disjunctive syllogism (also known as disjunction elimination and or elimination, or abbreviated ∨E), is a valid rule of inference. If it is known that at least one of two statements is true, and that it is not the former that is true; we can infer that it has to be the latter that is true. Equivalently, if ''P'' is true or ''Q'' is true and ''P'' is false, then ''Q'' is true. The name "disjunctive syllogism" derives from its being a syllogism, a three-step argument, and the use of a logical disjunction (any "or" statement.) For example, "P or Q" is a disjunction, wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Modus Ponens
In propositional logic, (; MP), also known as (), implication elimination, or affirming the antecedent, is a deductive argument form and rule of inference. It can be summarized as "''P'' implies ''Q.'' ''P'' is true. Therefore, ''Q'' must also be true." ''Modus ponens'' is a mixed hypothetical syllogism and is closely related to another valid form of argument, '' modus tollens''. Both have apparently similar but invalid forms: affirming the consequent and denying the antecedent. Constructive dilemma is the disjunctive version of ''modus ponens''. The history of ''modus ponens'' goes back to antiquity. The first to explicitly describe the argument form ''modus ponens'' was Theophrastus. It, along with '' modus tollens'', is one of the standard patterns of inference that can be applied to derive chains of conclusions that lead to the desired goal. Explanation The form of a ''modus ponens'' argument is a mixed hypothetical syllogism, with two premises and a con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Principle Of Explosion
In classical logic, intuitionistic logic, and similar logical systems, the principle of explosion is the law according to which any statement can be proven from a contradiction. That is, from a contradiction, any proposition (including its negation) can be inferred; this is known as deductive explosion. The proof of this principle was first given by 12th-century French philosopher William of Soissons. Due to the principle of explosion, the existence of a contradiction ( inconsistency) in a formal axiomatic system is disastrous; since any statement can be proven, it trivializes the concepts of truth and falsity. Around the turn of the 20th century, the discovery of contradictions such as Russell's paradox at the foundations of mathematics thus threatened the entire structure of mathematics. Mathematicians such as Gottlob Frege, Ernst Zermelo, Abraham Fraenkel, and Thoralf Skolem put much effort into revising set theory to eliminate these contradictions, resulting in the mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
