Search results
Results from the WOW.Com Content Network
It encodes the common concept of relation: an element is related to an element , if and only if the pair (,) belongs to the set of ordered pairs that defines the binary relation. An example of a binary relation is the "divides" relation over the set of prime numbers and the set of integers, in which each prime is related to each integer that is ...
A logical matrix, binary matrix, relation matrix, Boolean matrix, or (0, 1)-matrix is a matrix with entries from the Boolean domain B = {0, 1}. Such a matrix can be used to represent a binary relation between a pair of finite sets. It is an important tool in combinatorial mathematics and theoretical computer science.
A function that is injective. For example, the green relation in the diagram is an injection, but the red, blue and black ones are not. A surjection [d] A function that is surjective. For example, the green relation in the diagram is a surjection, but the red, blue and black ones are not. A bijection [d] A function that is injective and surjective.
A symmetric relation is a type of binary relation. Formally, a binary relation R over a set X is symmetric if: [1], (), where the notation aRb means that (a, b) ∈ R. An example is the relation "is equal to", because if a = b is true then b = a is also true.
Russell noted that binary relation aRb has a sense proceeding from a to b with the converse relation having an opposite sense, and sense "is the source of order and series." (p 95) He acknowledges Immanuel Kant [ 3 ] was "aware of the difference between logical opposition and the opposition of positive and negative".
[1] [2] [3] This is commonly phrased as "a relation on X" [4] or "a (binary) relation over X". [5] [6] An example of a homogeneous relation is the relation of kinship, where the relation is between people. Common types of endorelations include orders, graphs, and equivalences.
Properties of binary relations (4 C, 22 P) Pages in category "Binary relations" The following 26 pages are in this category, out of 26 total.
The usual composition of two binary relations as defined here can be obtained by taking their join, leading to a ternary relation, followed by a projection that removes the middle component. For example, in the query language SQL there is the operation join (SQL) .