When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Impredicativity - Wikipedia

    en.wikipedia.org/wiki/Impredicativity

    He states that his 6 or so (famous) examples of paradoxes (antinomies) are all examples of impredicative definition, and says that Poincaré (1905–6, 1908) and Russell (1906, 1910) "enunciated the cause of the paradoxes to lie in these impredicative definitions" (p. 42), however, "parts of mathematics we want to retain, particularly analysis ...

  3. Isbell duality - Wikipedia

    en.wikipedia.org/wiki/Isbell_duality

    Starr, Jason (2020), "Some Notes on Category Theory in MAT 589 Algebraic Geometry" (PDF), math.stonybrook.edu; Valence, Arnaud (2017), Esquisse d'une dualité géométrico-algébrique multidisciplinaire : la dualité d'Isbell, Thèse en cotutelle en Philosophie – Étude des Systèmes, soutenue le 30 mai 2017. (PDF) "Isbell duality", ncatlab.org

  4. Opposite category - Wikipedia

    en.wikipedia.org/wiki/Opposite_category

    In category theory, a branch of mathematics, the opposite category or dual category C op of a given category C is formed by reversing the morphisms, i.e. interchanging the source and target of each morphism. Doing the reversal twice yields the original category, so the opposite of an opposite category is the original category itself.

  5. Dual (category theory) - Wikipedia

    en.wikipedia.org/wiki/Dual_(category_theory)

    In category theory, a branch of mathematics, duality is a correspondence between the properties of a category C and the dual properties of the opposite category C op.Given a statement regarding the category C, by interchanging the source and target of each morphism as well as interchanging the order of composing two morphisms, a corresponding dual statement is obtained regarding the opposite ...

  6. Proof by contradiction - Wikipedia

    en.wikipedia.org/wiki/Proof_by_contradiction

    A typical example is the proof of the proposition "there is no smallest positive rational number": assume there is a smallest positive rational number q and derive a contradiction by observing that ⁠ q / 2 ⁠ is even smaller than q and still positive.

  7. List of mathematical constants - Wikipedia

    en.wikipedia.org/wiki/List_of_mathematical_constants

    For example, the constant π may be defined as the ratio of the length of a circle's circumference to its diameter. The following list includes a decimal expansion and set containing each number, ordered by year of discovery. The column headings may be clicked to sort the table alphabetically, by decimal value, or by set.

  8. Symmetric difference - Wikipedia

    en.wikipedia.org/wiki/Symmetric_difference

    In mathematics, the symmetric difference of two sets, also known as the disjunctive union and set sum, is the set of elements which are in either of the sets, but not in their intersection. For example, the symmetric difference of the sets {,,} and {,} is {,,}.

  9. Opposite - Wikipedia

    en.wikipedia.org/wiki/Opposite

    For example, something that is even entails that it is not odd. It is referred to as a 'binary' relationship because there are two members in a set of opposites. The relationship between opposites is known as opposition. A member of a pair of opposites can generally be determined by the question What is the opposite of X ?