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In the example below, the divide operation will return every tuple from the first relation that matches all tuples of the
second relation.
Student Task
Student Task
Vivek Studying plant growth Task Name
Vivek Creating games Studying plant growth
Jimmy Floor duty Creating games
Jimmy Creating games
Sudha Studying plant growth
Sudha Creating games
Student ÷ Task (Students who completed all tasks given in Relation Task).
Vivek
Sudha
Set Operations
When two or more sets are combined to form another set according to the mathematical principles of sets, the
process is called set operation. Let us study the four important set operations:
Set Union
The union of two sets A and B is the set of elements that are in A, in B, or in both A and B. It
is denoted by A U B. For example: If A = {20, 21, 22, 23} and B = {23, 24, 25}, then:
A ∪ B = {20, 21, 22, 23, 24, 25}. (The common elements occur only once).
A B
Set Intersection
The intersection of sets A and B is the set of elements that are common in A and B. It is
denoted by A ∩ B. For example:
If A = {21, 22, 23} and B = {23, 24, 25}, then A ∩ B = {23}.
A B
Set Difference
The difference between two sets is the set containing elements that are in A but not in B. It
is denoted by A – B.
For example:
A B
A = {21, 22, 23, 24, 25} and B = {22, 24, 26, 28}, then A – B = {21, 23, 25}.
Complement of Set
The complement of a set A (denoted by A’) is the set of elements that are not in set A. A’= (U - A) where U is a universal
set that contains all objects. For example:
Let U = {1, 2, 3, 4, 5, 6, 7, 8, 9} and A = {2, 4, 6, 8}
Then A’ = {1, 3, 5, 7, 9}.
Maths for AI 175

