• Thumbnail for Partially ordered set
    transitive. A partially ordered set (poset for short) is an ordered pair P = ( X , ≤ ) {\displaystyle P=(X,\leq )} consisting of a set X {\displaystyle...
    40 KB (5,378 words) - 18:33, 25 February 2025
  • the partially ordered set is a set of subsets of a given set that is ordered by inclusion, and the term is used for stating properties of the set of the...
    22 KB (3,150 words) - 14:08, 21 April 2025
  • In abstract algebra, a partially ordered group is a group (G, +) equipped with a partial order "≤" that is translation-invariant; in other words, "≤"...
    8 KB (1,122 words) - 05:46, 13 December 2024
  • and combinatorics, Dilworth's theorem states that, in any finite partially ordered set, the maximum size of an antichain of incomparable elements equals...
    18 KB (2,445 words) - 18:06, 31 December 2024
  • used to refer to at least three similar, but distinct, classes of partially ordered sets, characterized by particular completeness properties. Complete partial...
    11 KB (1,428 words) - 09:22, 13 November 2024
  • mathematical symbols Order theory Partially ordered set Directional symbols Polynomial-time reduction Cooley, Brandon. "Ordered Sets" (PDF) (Lecture note for:...
    7 KB (193 words) - 10:53, 12 February 2024
  • Thumbnail for Tree (set theory)
    In set theory, a tree is a partially ordered set ( T , < ) {\displaystyle (T,<)} such that for each t ∈ T {\displaystyle t\in T} , the set { s ∈ T : s...
    12 KB (1,558 words) - 21:33, 10 April 2025
  • Thumbnail for Maximal and minimal elements
    {\displaystyle S} is again defined dually. In the particular case of a partially ordered set, while there can be at most one maximum and at most one minimum...
    18 KB (3,135 words) - 15:05, 5 May 2024
  • is a fundamental property of the real numbers. More generally, a partially ordered set X has the least-upper-bound property if every non-empty subset of...
    12 KB (1,470 words) - 13:11, 11 September 2024
  • Thumbnail for Zorn's lemma
    Zorn's lemma (category Lemmas in set theory)
    proposition of set theory. It states that a partially ordered set containing upper bounds for every chain (that is, every totally ordered subset) necessarily...
    32 KB (4,668 words) - 17:57, 12 March 2025
  • In the mathematical field of order theory, an element a of a partially ordered set with least element 0 is an atom if 0 < a and there is no x such that...
    3 KB (361 words) - 01:40, 17 June 2024
  • a partially ordered set such that any two distinct elements in the subset are incomparable. The size of the largest antichain in a partially ordered set...
    8 KB (1,090 words) - 11:19, 27 February 2023
  • Thumbnail for Upper set
    In mathematics, an upper set (also called an upward closed set, an upset, or an isotone set in X) of a partially ordered set ( X , ≤ ) {\displaystyle...
    9 KB (1,291 words) - 14:07, 1 February 2023
  • then a ≤ c (transitivity). A set with a partial order on it is called a partially ordered set, poset, or just ordered set if the intended meaning is clear...
    31 KB (4,510 words) - 13:16, 14 April 2025
  • subdisciplines of order theory and abstract algebra. It consists of a partially ordered set in which every pair of elements has a unique supremum (also called...
    41 KB (5,834 words) - 13:33, 28 April 2025
  • Thumbnail for Hasse diagram
    Hasse diagram (category Graphical concepts in set theory)
    represent a finite partially ordered set, in the form of a drawing of its transitive reduction. Concretely, for a partially ordered set ( S , ≤ ) {\displaystyle...
    11 KB (1,342 words) - 10:38, 16 December 2024
  • Cofinality (category Set theory)
    mathematics, especially in order theory, the cofinality cf(A) of a partially ordered set A is the least of the cardinalities of the cofinal subsets of A...
    8 KB (1,345 words) - 05:54, 25 February 2025
  • Thumbnail for Join and meet
    specifically order theory, the join of a subset S {\displaystyle S} of a partially ordered set P {\displaystyle P} is the supremum (least upper bound) of S , {\displaystyle...
    13 KB (2,262 words) - 22:59, 20 March 2025
  • (abbreviated inf; pl.: infima) of a subset S {\displaystyle S} of a partially ordered set P {\displaystyle P} is the greatest element in P {\displaystyle...
    25 KB (4,523 words) - 14:12, 31 December 2024
  • (Y):Y\subseteq X{\text{ and }}Y{\text{ finite}}\right\}.} In the theory of partially ordered sets, which are important in theoretical computer science, closure operators...
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  • any partially ordered set, every totally ordered subset is contained in a maximal totally ordered subset, where "maximal" is with respect to set inclusion...
    11 KB (2,015 words) - 14:36, 17 December 2024
  • Thumbnail for Bounded set
    set of real numbers is bounded if and only if it has an upper and lower bound. This definition is extendable to subsets of any partially ordered set....
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  • Thumbnail for Dedekind cut
    mathematician Norberto Cuesta Dutari [es]. More generally, if S is a partially ordered set, a completion of S means a complete lattice L with an order-embedding...
    13 KB (2,069 words) - 10:45, 13 March 2025
  • Thumbnail for Greatest element and least element
    theory, the greatest element of a subset S {\displaystyle S} of a partially ordered set (poset) is an element of S {\displaystyle S} that is greater than...
    17 KB (2,870 words) - 17:45, 2 June 2024
  • Thumbnail for Weak ordering
    (rankings without ties) and are in turn generalized by (strictly) partially ordered sets and preorders. There are several common ways of formalizing weak...
    30 KB (4,360 words) - 12:57, 6 October 2024
  • chain is a totally ordered set or a totally ordered subset of a poset. See also total order. Chain complete. A partially ordered set in which every chain...
    29 KB (4,204 words) - 03:05, 12 April 2025
  • Thumbnail for Subdivision (simplicial set)
    s(I)} be the set of non-empty finite totally ordered subsets, which itself is partially ordered by inclusion. Every partially ordered set can be considered...
    7 KB (977 words) - 18:44, 28 April 2025
  • Thumbnail for Dedekind–MacNeille completion
    specifically order theory, the Dedekind–MacNeille completion of a partially ordered set is the smallest complete lattice that contains it. It is named after...
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  • Directed sets are a generalization of nonempty totally ordered sets. That is, all totally ordered sets are directed sets (contrast partially ordered sets, which...
    16 KB (2,794 words) - 05:37, 2 December 2024
  • In order-theoretic mathematics, a graded partially ordered set is said to have the Sperner property (and hence is called a Sperner poset), if no antichain...
    2 KB (260 words) - 17:29, 17 March 2023