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Preorder

Index Preorder

In mathematics, especially in order theory, a preorder or quasiorder is a binary relation that is reflexive and transitive. [1]

Table of Contents

  1. 82 relations: Abstract rewriting system, Alexandrov topology, Antisymmetric relation, Asymmetric relation, Big O notation, Bijection, Binary relation, Category (mathematics), Category of preordered sets, Class (set theory), Commutative ring, Complement (set theory), Composition of relations, Connected relation, Consistency, Converse relation, Cycle (graph theory), Directed acyclic graph, Directed graph, Directed set, Division (mathematics), Embedding, Encompassment ordering, Enriched category, Equivalence class, Equivalence relation, Finite topological space, Forcing (mathematics), Graph minor, Greatest common divisor, Independence (mathematical logic), Injective function, Interior algebra, Interval (mathematics), Kripke semantics, Least common multiple, Lindenbaum–Tarski algebra, Logical conjunction, Logical equivalence, Many-one reduction, Mathematics, Modal logic, Modus ponens, Morphism, Neighbourhood (mathematics), Net (mathematics), Order theory, Partially ordered set, Path (graph theory), Permutation, ... Expand index (32 more) »

  2. Properties of binary relations

Abstract rewriting system

In mathematical logic and theoretical computer science, an abstract rewriting system (also (abstract) reduction system or abstract rewrite system; abbreviated ARS) is a formalism that captures the quintessential notion and properties of rewriting systems.

See Preorder and Abstract rewriting system

Alexandrov topology

In topology, an Alexandrov topology is a topology in which the intersection of every family of open sets is open. Preorder and Alexandrov topology are order theory.

See Preorder and Alexandrov topology

Antisymmetric relation

In mathematics, a binary relation R on a set X is antisymmetric if there is no pair of distinct elements of X each of which is related by R to the other. Preorder and antisymmetric relation are properties of binary relations.

See Preorder and Antisymmetric relation

Asymmetric relation

In mathematics, an asymmetric relation is a binary relation R on a set X where for all a, b \in X, if a is related to b then b is not related to a. Preorder and asymmetric relation are properties of binary relations.

See Preorder and Asymmetric relation

Big O notation

Big O notation is a mathematical notation that describes the limiting behavior of a function when the argument tends towards a particular value or infinity.

See Preorder and Big O notation

Bijection

A bijection, bijective function, or one-to-one correspondence between two mathematical sets is a function such that each element of the first set (the domain) is mapped to exactly one element of the second set (the codomain).

See Preorder and Bijection

Binary relation

In mathematics, a binary relation associates elements of one set, called the domain, with elements of another set, called the codomain.

See Preorder and Binary relation

Category (mathematics)

In mathematics, a category (sometimes called an abstract category to distinguish it from a concrete category) is a collection of "objects" that are linked by "arrows".

See Preorder and Category (mathematics)

Category of preordered sets

In mathematics, the category Ord has preordered sets as objects and order-preserving functions as morphisms.

See Preorder and Category of preordered sets

Class (set theory)

In set theory and its applications throughout mathematics, a class is a collection of sets (or sometimes other mathematical objects) that can be unambiguously defined by a property that all its members share.

See Preorder and Class (set theory)

Commutative ring

In mathematics, a commutative ring is a ring in which the multiplication operation is commutative.

See Preorder and Commutative ring

Complement (set theory)

In set theory, the complement of a set, often denoted by A^\complement, is the set of elements not in.

See Preorder and Complement (set theory)

Composition of relations

In the mathematics of binary relations, the composition of relations is the forming of a new binary relation from two given binary relations R and S. In the calculus of relations, the composition of relations is called relative multiplication, and its result is called a relative product.

See Preorder and Composition of relations

Connected relation

In mathematics, a relation on a set is called connected or complete or total if it relates (or "compares") all pairs of elements of the set in one direction or the other while it is called strongly connected if it relates pairs of elements. Preorder and connected relation are properties of binary relations.

See Preorder and Connected relation

Consistency

In classical deductive logic, a consistent theory is one that does not lead to a logical contradiction.

See Preorder and Consistency

Converse relation

In mathematics, the converse of a binary relation is the relation that occurs when the order of the elements is switched in the relation.

See Preorder and Converse relation

Cycle (graph theory)

In graph theory, a cycle in a graph is a non-empty trail in which only the first and last vertices are equal.

See Preorder and Cycle (graph theory)

Directed acyclic graph

In mathematics, particularly graph theory, and computer science, a directed acyclic graph (DAG) is a directed graph with no directed cycles.

See Preorder and Directed acyclic graph

Directed graph

In mathematics, and more specifically in graph theory, a directed graph (or digraph) is a graph that is made up of a set of vertices connected by directed edges, often called arcs.

See Preorder and Directed graph

Directed set

In mathematics, a directed set (or a directed preorder or a filtered set) is a nonempty set A together with a reflexive and transitive binary relation \,\leq\, (that is, a preorder), with the additional property that every pair of elements has an upper bound. Preorder and directed set are order theory.

See Preorder and Directed set

Division (mathematics)

Division is one of the four basic operations of arithmetic.

See Preorder and Division (mathematics)

Embedding

In mathematics, an embedding (or imbedding) is one instance of some mathematical structure contained within another instance, such as a group that is a subgroup. Preorder and embedding are order theory.

See Preorder and Embedding

Encompassment ordering

In theoretical computer science, in particular in automated theorem proving and term rewriting, the containment, or encompassment, preorder (≤) on the set of terms, is defined by It is used e.g. in the Knuth–Bendix completion algorithm. Preorder and encompassment ordering are order theory.

See Preorder and Encompassment ordering

Enriched category

In category theory, a branch of mathematics, an enriched category generalizes the idea of a category by replacing hom-sets with objects from a general monoidal category.

See Preorder and Enriched category

Equivalence class

In mathematics, when the elements of some set S have a notion of equivalence (formalized as an equivalence relation), then one may naturally split the set S into equivalence classes.

See Preorder and Equivalence class

Equivalence relation

In mathematics, an equivalence relation is a binary relation that is reflexive, symmetric and transitive.

See Preorder and Equivalence relation

Finite topological space

In mathematics, a finite topological space is a topological space for which the underlying point set is finite.

See Preorder and Finite topological space

Forcing (mathematics)

In the mathematical discipline of set theory, forcing is a technique for proving consistency and independence results.

See Preorder and Forcing (mathematics)

Graph minor

In graph theory, an undirected graph is called a minor of the graph if can be formed from by deleting edges, vertices and by contracting edges.

See Preorder and Graph minor

Greatest common divisor

In mathematics, the greatest common divisor (GCD) of two or more integers, which are not all zero, is the largest positive integer that divides each of the integers.

See Preorder and Greatest common divisor

Independence (mathematical logic)

In mathematical logic, independence is the unprovability of a sentence from other sentences.

See Preorder and Independence (mathematical logic)

Injective function

In mathematics, an injective function (also known as injection, or one-to-one function) is a function that maps distinct elements of its domain to distinct elements; that is, implies.

See Preorder and Injective function

Interior algebra

In abstract algebra, an interior algebra is a certain type of algebraic structure that encodes the idea of the topological interior of a set.

See Preorder and Interior algebra

Interval (mathematics)

In mathematics, a (real) interval is the set of all real numbers lying between two fixed endpoints with no "gaps". Preorder and interval (mathematics) are order theory.

See Preorder and Interval (mathematics)

Kripke semantics

Kripke semantics (also known as relational semantics or frame semantics, and often confused with possible world semantics) is a formal semantics for non-classical logic systems created in the late 1950s and early 1960s by Saul Kripke and André Joyal.

See Preorder and Kripke semantics

Least common multiple

In arithmetic and number theory, the least common multiple, lowest common multiple, or smallest common multiple of two integers a and b, usually denoted by, is the smallest positive integer that is divisible by both a and b. Since division of integers by zero is undefined, this definition has meaning only if a and b are both different from zero.

See Preorder and Least common multiple

Lindenbaum–Tarski algebra

In mathematical logic, the Lindenbaum–Tarski algebra (or Lindenbaum algebra) of a logical theory T consists of the equivalence classes of sentences of the theory (i.e., the quotient, under the equivalence relation ~ defined such that p ~ q exactly when p and q are provably equivalent in T).

See Preorder and Lindenbaum–Tarski algebra

Logical conjunction

In logic, mathematics and linguistics, and (\wedge) is the truth-functional operator of conjunction or logical conjunction.

See Preorder and Logical conjunction

Logical equivalence

In logic and mathematics, statements p and q are said to be logically equivalent if they have the same truth value in every model.

See Preorder and Logical equivalence

Many-one reduction

In computability theory and computational complexity theory, a many-one reduction (also called mapping reduction) is a reduction that converts instances of one decision problem (whether an instance is in L_1) to another decision problem (whether an instance is in L_2) using a computable function.

See Preorder and Many-one reduction

Mathematics

Mathematics is a field of study that discovers and organizes abstract objects, methods, theories and theorems that are developed and proved for the needs of empirical sciences and mathematics itself.

See Preorder and Mathematics

Modal logic is a kind of logic used to represent statements about necessity and possibility.

See Preorder and Modal logic

Modus ponens

In propositional logic, modus ponens (MP), also known as modus ponendo ponens, implication elimination, or affirming the antecedent, is a deductive argument form and rule of inference.

See Preorder and Modus ponens

Morphism

In mathematics, a morphism is a concept of category theory that generalizes structure-preserving maps such as homomorphism between algebraic structures, functions from a set to another set, and continuous functions between topological spaces.

See Preorder and Morphism

Neighbourhood (mathematics)

In topology and related areas of mathematics, a neighbourhood (or neighborhood) is one of the basic concepts in a topological space.

See Preorder and Neighbourhood (mathematics)

Net (mathematics)

In mathematics, more specifically in general topology and related branches, a net or Moore–Smith sequence is a function whose domain is a directed set.

See Preorder and Net (mathematics)

Order theory

Order theory is a branch of mathematics that investigates the intuitive notion of order using binary relations.

See Preorder and Order theory

Partially ordered set

In mathematics, especially order theory, a partial order on a set is an arrangement such that, for certain pairs of elements, one precedes the other. Preorder and Partially ordered set are order theory.

See Preorder and Partially ordered set

Path (graph theory)

In graph theory, a path in a graph is a finite or infinite sequence of edges which joins a sequence of vertices which, by most definitions, are all distinct (and since the vertices are distinct, so are the edges).

See Preorder and Path (graph theory)

Permutation

In mathematics, a permutation of a set can mean one of two different things.

See Preorder and Permutation

Polynomial

In mathematics, a polynomial is a mathematical expression consisting of indeterminates (also called variables) and coefficients, that involves only the operations of addition, subtraction, multiplication and exponentiation to nonnegative integer powers, and has a finite number of terms.

See Preorder and Polynomial

Polynomial-time reduction

In computational complexity theory, a polynomial-time reduction is a method for solving one problem using another.

See Preorder and Polynomial-time reduction

Posetal category

In mathematics, specifically category theory, a posetal category, or thin category, is a category whose homsets each contain at most one morphism.

See Preorder and Posetal category

Preference

In psychology, economics and philosophy, preference is a technical term usually used in relation to choosing between alternatives.

See Preorder and Preference

Preordered class

In mathematics, a preordered class is a class equipped with a preorder. Preorder and preordered class are order theory.

See Preorder and Preordered class

Prewellordering

In set theory, a prewellordering on a set X is a preorder \leq on X (a transitive and reflexive relation on X) that is strongly connected (meaning that any two points are comparable) and well-founded in the sense that the induced relation x defined by x \leq y \text y \nleq x is a well-founded relation. Preorder and prewellordering are order theory.

See Preorder and Prewellordering

Propositional calculus

The propositional calculus is a branch of logic.

See Preorder and Propositional calculus

Reachability

In graph theory, reachability refers to the ability to get from one vertex to another within a graph.

See Preorder and Reachability

Reflexive closure

In mathematics, the reflexive closure of a binary relation R on a set X is the smallest reflexive relation on X that contains R. A relation is called if it relates every element of X to itself.

See Preorder and Reflexive closure

Reflexive relation

In mathematics, a binary relation R on a set X is reflexive if it relates every element of X to itself. Preorder and reflexive relation are properties of binary relations.

See Preorder and Reflexive relation

Ring homomorphism

In mathematics, a ring homomorphism is a structure-preserving function between two rings.

See Preorder and Ring homomorphism

Sentence (mathematical logic)

In mathematical logic, a sentence (or closed formula) of a predicate logic is a Boolean-valued well-formed formula with no free variables.

See Preorder and Sentence (mathematical logic)

Set (mathematics)

In mathematics, a set is a collection of different things; these things are called elements or members of the set and are typically mathematical objects of any kind: numbers, symbols, points in space, lines, other geometrical shapes, variables, or even other sets.

See Preorder and Set (mathematics)

Set theory

Set theory is the branch of mathematical logic that studies sets, which can be informally described as collections of objects.

See Preorder and Set theory

Simulation (computer science)

In theoretical computer science a simulation is a relation between state transition systems associating systems that behave in the same way in the sense that one system simulates the other.

See Preorder and Simulation (computer science)

Specialization (pre)order

In the branch of mathematics known as topology, the specialization (or canonical) preorder is a natural preorder on the set of the points of a topological space. Preorder and specialization (pre)order are order theory.

See Preorder and Specialization (pre)order

Substitution (logic)

A substitution is a syntactic transformation on formal expressions.

See Preorder and Substitution (logic)

Subtyping

In programming language theory, subtyping (also called subtype polymorphism or inclusion polymorphism) is a form of type polymorphism.

See Preorder and Subtyping

Surjective function

In mathematics, a surjective function (also known as surjection, or onto function) is a function such that, for every element of the function's codomain, there exists one element in the function's domain such that.

See Preorder and Surjective function

Symmetric relation

A symmetric relation is a type of binary relation. Preorder and symmetric relation are properties of binary relations.

See Preorder and Symmetric relation

Term (logic)

In mathematical logic, a term denotes a mathematical object while a formula denotes a mathematical fact.

See Preorder and Term (logic)

Theory (mathematical logic)

In mathematical logic, a theory (also called a formal theory) is a set of sentences in a formal language.

See Preorder and Theory (mathematical logic)

Theta-subsumption

Theta-subsumption (θ-subsumption, or just subsumption) is a decidable relation between two first-order clauses that guarantees that one clause logically entails the other.

See Preorder and Theta-subsumption

Topology

Topology (from the Greek words, and) is the branch of mathematics concerned with the properties of a geometric object that are preserved under continuous deformations, such as stretching, twisting, crumpling, and bending; that is, without closing holes, opening holes, tearing, gluing, or passing through itself.

See Preorder and Topology

Total order

In mathematics, a total order or linear order is a partial order in which any two elements are comparable. Preorder and total order are order theory and properties of binary relations.

See Preorder and Total order

Transitive closure

In mathematics, the transitive closure of a homogeneous binary relation on a set is the smallest relation on that contains and is transitive.

See Preorder and Transitive closure

Transitive relation

In mathematics, a binary relation on a set is transitive if, for all elements,, in, whenever relates to and to, then also relates to.

See Preorder and Transitive relation

Turing reduction

In computability theory, a Turing reduction from a decision problem A to a decision problem B is an oracle machine that decides problem A given an oracle for B (Rogers 1967, Soare 1987).

See Preorder and Turing reduction

Upper and lower bounds

In mathematics, particularly in order theory, an upper bound or majorant of a subset of some preordered set is an element of that is every element of. Preorder and upper and lower bounds are order theory.

See Preorder and Upper and lower bounds

Weak ordering

In mathematics, especially order theory, a weak ordering is a mathematical formalization of the intuitive notion of a ranking of a set, some of whose members may be tied with each other. Preorder and weak ordering are order theory and properties of binary relations.

See Preorder and Weak ordering

Well-quasi-ordering

In mathematics, specifically order theory, a well-quasi-ordering or wqo on a set X is a quasi-ordering of X for which every infinite sequence of elements x_0, x_1, x_2, \ldots from X contains an increasing pair x_i \leq x_j with i. Preorder and well-quasi-ordering are order theory.

See Preorder and Well-quasi-ordering

Zermelo–Fraenkel set theory

In set theory, Zermelo–Fraenkel set theory, named after mathematicians Ernst Zermelo and Abraham Fraenkel, is an axiomatic system that was proposed in the early twentieth century in order to formulate a theory of sets free of paradoxes such as Russell's paradox.

See Preorder and Zermelo–Fraenkel set theory

See also

Properties of binary relations

References

[1] https://en.wikipedia.org/wiki/Preorder

Also known as Precongruence, Preorder (mathematics), Preordered set, Quasi order, Quasi-order, Quasi-ordering, Quasiorder, Strict preorder.

, Polynomial, Polynomial-time reduction, Posetal category, Preference, Preordered class, Prewellordering, Propositional calculus, Reachability, Reflexive closure, Reflexive relation, Ring homomorphism, Sentence (mathematical logic), Set (mathematics), Set theory, Simulation (computer science), Specialization (pre)order, Substitution (logic), Subtyping, Surjective function, Symmetric relation, Term (logic), Theory (mathematical logic), Theta-subsumption, Topology, Total order, Transitive closure, Transitive relation, Turing reduction, Upper and lower bounds, Weak ordering, Well-quasi-ordering, Zermelo–Fraenkel set theory.