Maths for Regular expression (Regex) Flashcards
What is a set
A set is a defined list of elements.
Properties of a set
A set is unordered and each element only appears once
Advantages of using a set
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
What are the common number sets
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
What does the ε symbol mean
x ε S
Means that x is apart of set S
What does the ∧ symbol mean
And
What does the | symbol mean
Such that
What is a subset
Where every element of set A is present in set B
What is a proper subset
Where set A is a subset of set B but is not the same
What are the operations of a set
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
What is the cartesian product
Set of all ordered pairs
A x B
What is a finite set
A set that is limited in amount of elements.
The cardinality being the number of elements
