A set is a group of well specified things. Only on the basis of simplicity are the objects in a set considered distinct.
A family or collection of sets is another term for a group of sets. For example, suppose we had a set family consisting of A1, A2, A3,….. up to An, which we can express as {A1, A2, A3,….., An}.
S = {Ai | i belongs to n and 1 ≤ i ≤ n}
Sets
A set is represented by listing all of its elements between curly brackets and marked by a capital letter, such as.
Types of sets
Empty set: An empty set is one with no elements or cardinality zero.
Finite set: A finite set is one with a finite number of items, such as A = 1, 2, 3.
Infinite set: An unlimited set is one with an infinite number of items, such as B = 1, 2, 3,…
Equal sets are two sets that share the same items and have the same cardinality.
Relations
The connection is a subset of the Cartesian product that only comprises some of the ordered pairs dependent on the first and second component’s relationships. R is commonly used to represent the relationship.
This form of relation qualifies as a function if every element of a set A is related to one and only one element of another set. A function is a type of relationship in which no two ordered pairs can share the same initial element.
The notation f:X→Y indicates that f is a function that goes from X to Y. There is only one y∈Y for x∈X, and his y is written as y = f(x), which indicates the value of f at x, which is the value of y at a certain value of x.
Types of Relations
Reflexive: If ∀ x ∊ X, (x, x) ∊ R., a relation R is reflexive.
Symmetric: A symmetric relation R is one in which (a, b) R implies (b, a) R.
Transitive: A relation R is transitive if it entails (a, b) ∊ R and (b, c)∊R.
R is an equivalence relation if it is reflexive, symmetric, and transitive.
Identity: If R = {(x, x):x ∊ X}. then it is an identity.
Interconnection between Sets and Relations
Sets and relationships are inextricably linked. The relationship between two sets is defined by the relation.
When there are two sets accessible, we use relations to see if there is a connection between them.
An empty relation, for example, means that none of the elements in the two sets are the same.
Connection between Sets and Relations
Relationships, sets, and functions All three subjects are intertwined. Sets are collections of ordered elements, whereas relations and functions are the actions that may be performed on them.
The relations establish the link between the two sets. There are also other sorts of relations that describe the links between the sets.
Relations and Functions related to sets
A relation aids in the linking of elements from two sets so that the input and output form an ordered pair (input, output). A function is a subset of a relationship that determines the output given a particular input. All relations are functions, but not all functions are relations. R = { (1, 2), (1, 3), (2, 3)} is a relation rather than a function because 1 is mapped twice (to both 2 and 3). It is self-evident that for a legitimate function, each domain component must point to only one range member. As a result, for the provided relation, it is evident that one domain component is linked to more than two range items. As a result, this relationship is not a function.
So far, each domain component must tend to one element in the range that is satisfied according to the condition, however one domain element is not matched with any of the range elements. If every element of the set X is related with exactly one element of the set Y, the relation from set X to set Y represents a function.
Conclusion
Sets let you define “intrinsic” object properties. We can make a statement about this item by reasoning about how this object behaves under certain situations since they are members of a given set. Sets are frequently used to define fundamental axioms, which are then used to deduce more common mathematical concepts. This concept of properties is expanded to include how objects from one or more sets interact with one another. They can be used to define algebraic functions, binary operations, and graphs all within the same syntactic framework because of their universality.