Maths for Regular expression (Regex)

Question 1

What is a set

Answer 1

A set is a defined list of elements.

Question 2

Properties of a set

Answer 2

A set is unordered and each element only appears once

Question 3

Advantages of using a set

Answer 3

A tool for abstraction
Close relation with set theory and logic
Helps the basis of algebra
Many programming languages supports sets as abstract data type

Question 4

What are the common number sets

Answer 4

N - Natural numbers (0,1,2,3,4,…)
Z+ - Real positive integers (1,2,3,..)
Z - All integers (…,-2,-1,0,1,2,..)
Q - Set of rational numbers
R - Set of real numbers
∅ - Empty set

Question 5

What does the ε symbol mean

Answer 5

x ε S

Means that x is apart of set S

Question 6

What does the ∧ symbol mean

Answer 6

And

Question 7

What does the | symbol mean

Answer 7

Such that

Question 8

What is a subset

Answer 8

Where every element of set A is present in set B

Question 9

What is a proper subset

Answer 9

Where set A is a subset of set B but is not the same

Question 10

What are the operations of a set

Answer 10

Union (AUB)- Set of elements in either A or B or both

Intersection (A∩B)- Set of elements in A and B

Difference (A\B) - Set of elements in A but not in B

Question 11

What is the cartesian product

Answer 11

Set of all ordered pairs
A x B

Question 12

What is a finite set

Answer 12

A set that is limited in amount of elements.
The cardinality being the number of elements