• 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 (5,351 words) - 15:10, 28 June 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 (3,100 words) - 10:51, 4 June 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 (1,112 words) - 12:40, 24 May 2025
  • used to refer to at least three similar, but distinct, classes of partially ordered sets, characterized by particular completeness properties. Complete partial...
    11 KB (1,422 words) - 08:25, 28 July 2025
  • 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
  • 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) - 20:13, 13 July 2025
  • 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
  • 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
  • any partially ordered set, every totally ordered subset is contained in a maximal totally ordered subset, where "maximal" is with respect to set inclusion...
    13 KB (2,424 words) - 02:29, 14 July 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
  • 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
  • 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...
    39 KB (5,451 words) - 17:40, 29 June 2025
  • 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 (4,674 words) - 18:53, 27 July 2025
  • 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
  • (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) - 04:35, 26 July 2025
  • 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 (4,490 words) - 06:40, 21 June 2025
  • 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 (1,465 words) - 01:39, 2 July 2025
  • (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...
    19 KB (2,656 words) - 21:44, 19 June 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...
    22 KB (2,726 words) - 09:57, 21 May 2025
  • Thumbnail for Filter (mathematics)
    mathematics, a filter or order filter is a special subset of a partially ordered set (poset), describing "large" or "eventual" elements. Filters appear...
    24 KB (2,819 words) - 21:20, 27 July 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
  • 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
  • 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 (1,290 words) - 14:45, 19 June 2025
  • 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
  • mathematical area of order theory, every partially ordered set P gives rise to a dual (or opposite) partially ordered set which is often denoted by Pop or Pd...
    4 KB (457 words) - 00:47, 21 September 2023
  • 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 (2,678 words) - 09:53, 28 July 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) - 12:36, 3 June 2025
  • 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
  • In mathematical order theory, an ideal is a special subset of a partially ordered set (poset). Although this term historically was derived from the notion...
    13 KB (1,762 words) - 08:42, 16 June 2025
  • 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 (2,070 words) - 06:51, 23 July 2025