Automata M1-M3 Flashcards

1
Q

as a collection well defined objects, called elements having certain common property

A

Sets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

represented by a CAPITAL letter, i.e. A, B, C

A

Sets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

In sets, order of elements is _____

A

insignificant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

In sets, it does not matter how often the same element is ________

A

listed (repetition doesn’t count)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Two types of Method of Set Notation:

A

Roster / Tabular / List Method
Set Builder / Rule Method
Venn Diagram

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

the set is represented by actually listing the elements which belong to it

A

Roster / Tabular / List Method

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

separated by comma (,) and enclosed between pair of curly brackets { }.

A

Roster / Tabular / List Method

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

The order of writing the elements of set is immaterial

A

Roster / Tabular / List Method

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Roster method is used only when the number of elements in the set is _______

A

finite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

sometimes a set is defined by stating property (P) which characterizes all the elements of the set.

A

Set Builder / Rule Method

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

the elements must satisfy a given rule or condition

A

Set Builder / Rule Method

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

It represents relation and operator using the plan geometrical figures such as rectangle, circle, ellipse

A

Venn Diagram

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Types of Sets

A

Finite Set
Infinite Set
Empty Set
Unit Set
Subset (⊆)
Proper Subset
Family Set
Power Set
Universal Set
Complement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

a set whose elements are countable

A

Finite Set

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

a set whose elements are not countable

A

Infinite Set

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

a set having no element.

A

Empty Set

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Its also called as null set or void set

A

Empty Set

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

It is denoted by Ø or {}.

A

Empty Set

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

a set containing only one element.

A

Unit Set

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

It is also called a singleton.

A

Unit Set

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

If each element of the set A is also an element of set B.

A

Subset (⊆)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

The set A ⊂ B and A ≠ B, then A is called a ______ of B

A

Proper Subset

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

or Set A is a ______ of set B if there is at least one element in B not contained in A.

A

proper subset

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

class of sets or the set of sets

A

Family Set

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

the set of all subsets of a given set.

A

Power Set

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

It is denoted by P(A) where number of subsets equal to 2^|A|.

A

Power Set

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

a set which contains all objects, including itself

A

Universal Set (U)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

The ________ of set A, written as “A is the set containing everything that is not in A.”

A

Complement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

N = {0, 1, 2, 3, …}

A

Natural Numbers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Z = {…, -2, -1, 0, 1, 2, …}

A

Integers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Z^+ = {1, 2, 3, 4, …}

A

Positive Integers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Q = {1.5, 2.6, -3.8, 15, …}

A

Rational Numbers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

R = {47.3, -12, π, …}

A

Real Numbers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

For numbers with decimal places, it must be ____

A

terminating or as recurring decimal digits for non-terminating type

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Set Relations:

A

Equal Sets
Equivalent Sets
Disjoint Sets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

two sets A and B consisting of the same elements and same cardinality

A

Equal Sets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

two sets A and B having the same cardinality.

A

Equivalent Sets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

the two sets having no common elements

A

Disjoint Set

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Set Operations:

A

Union
Intersection
Sett Difference

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

A U B = {x | (x ∊ A) or (x ∊ B) }

A

Union

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

The ______ of sets A and B, written A ⋂ B, is a set that contains exactly those elements that are in both A and B

A

Intersection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

A ⋂ B = {x | (x ∈ A) and (x ∈ B)}

A

Intersection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

The _______ of set A and set B, written as A - B, is the set that contains everything that is in A but not in B.

A

Set Difference

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

A - B = {x | x ∈ A and x ∉ B}

A

Set Difference

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

–– is what

A

complement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

A ____ on sets S and T is a set of ordered pairs (s, t),

A

relation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

A relation on sets S and T is a set of ordered pairs (s, t), where:

A

s ∊ S (s is a member of S)
t ∊ T
S and T need not be different
The set of all first elements is the “domain” of the relation and
The set of all second elements is the “range” of the relation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

R1 = {(a, b) | (a < b)} = {(1,2), (1,3), (2,3)}
R2 = {(a, b) | a = b)} = {(1,1), (2,2), (3,3)}
R3 = {(a, b) | b = 4a) = { }
R4 = {(1,1), (1,2), (1,3), (2,1), (2,2), (2,3), (3,1), (3,2), (3,3)}

A

R2 is called identity relation
R3 is called void relation
R4 is called universal relation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

A subset R of A is called an equivalence relation on A if R satisfies the following conditions:

A

Equivalence Relation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

A subset R of A is called an equivalence relation on A if R satisfies the following conditions:

A

(i) (a,a) ∊ R for all a ∊ A (R is reflexive)
(ii) If (a, b) ∊ R, then (b, a) ∊ R, then (a, b) ∊ R (R is symmetric)
(iii) If (a, b) ∊ R and (b, c) ∊ R, then (a, c) ∊ R (R is transitive)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

A ______is a way of matching the members of a set “A” to a set “B”:

A

function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Each element of A should be associated to exactly one element of B, though more A may be associated in B.

A

Functions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Every element of A must be associated with unique element of B

A

Functions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

May be some elements of set B which are not assigned to any element of set A

A

Functions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Every _____ is a ______
Not all _____ are _____

A

function, relation
relation. function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

One-to-one (______) correspondence function

A

injective

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

if each element of B is f image of at least one element of A f(a) = b

A

Onto (surjective)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

(if there is one element of B which is not f image of any element of A)

A

Into function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

(mapped to the same single element of B)

A

Constant Function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

With a constant function, for any two points in the interval, a change in x results in a zero change in f(x)

A

Constant Function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

mapped into itself

A

Identity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

Representations of Relations

A

Relation as arrow diagram
Relation as table
Relation as matrix
Relation as Directed Graph

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

Types of Function

A

One-to-one (injective) correspondence function
Onto (Surjective)
Into
Constant
Identity
Invertible Function
Inclusion Function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

A function whose domain is a subset of its codomain, and for which all the elements in its domain are fixed points

A

Inclusion Function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

A _____ is a bunch of vertices (Nodes) which are represented by circles and are connected by edges represented by lines

A

Graph

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

are undirected graphs

A

Trees

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

Any two vertices are connected by exactly one simple path.

A

Trees

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

A _____ also does not contain cycle

A

tree

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

A _____ G = (V, E)

A

simple graph

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

{set of all vertices} - not empty

A

V

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

{set of all edges} - not empty

A

E

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

{subsets of V with cardinality 2}

A

E

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

2 Types of Digraph

A

In-degree
Out-degree

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

a pair of vertices that determine an edge are ____ vertices

A

“adjacent”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

in a graph G consists of a pair (V, E) of sequences

A

Path

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

is a path that begins and ends at the same vertex

A

Circuit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

A path is called ______ if no vertex appears more than once in the vertex sequence

A

simple

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

a graph is called ______ if there is a path from any vertex to any other vertex in the graph, otherwise, the graph is “disconnected”.

A

Connected Graph

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

if the graph is ______, the various connected pieces are called the components of the graph

A

Component

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

A Graph is said to be a _____ if it is connected and has no simple cycles

A

Tree

81
Q

is one that does not repeat any node except for the first and last

A

Simple Cycle

82
Q

is the study of abstract computing device, or “machines”.

A

Automata Theory

83
Q

It deals with the logic of computation with respect to simple machines, referred to as ____

A

Automata Theory

84
Q

It deals with the definitions and properties of mathematical models of computation such as Finite Automaton and Context-Free Grammar

A

Automata Theory

85
Q

Through ______, computer scientists are able to understand how machines compute functions and solve problems

A

automata

86
Q

Conceived the first infinite model of computation in 1936

A
  • Alan Turing
87
Q

First to present a description of finite automata in 1943:

A
  • Warren McCulloch
  • Walter Pitts
88
Q

Generalized automata theory to a much more powerful machine in 1955:

A

G. H. Mealy

89
Q

Applications of Automata and Formal Languages

A

It serves as a preparation and introduction to circuit design.
Knowledge of automata is very important in designing compilers
Regular expressions in automata provide a thousand and one uses for professional programmers
Searching for patterns in texts can be carried out efficiently using automata
Automata and its formal languages are useful in natural language processing
Algebraic theory of recognizable language can be developed using automata theory and its languages

90
Q

Terminologies in Automata

A

Alphabet
String
Concatenation of two strings
Length of a string
Empty String
Reverse String
Substring
Suffix
Prefix
Lexicographic ordering
Language
Concatenation of Language
Powers of an Alphabet
State

91
Q

A finite, nonempty set of symbols. Denoted by Σ. whose elements are called symbols

A

Alphabet

92
Q

Alphabet is a finite, nonempty set of symbols. Denoted by Σ. whose elements are called _____

A

symbols

93
Q

denotes set of all nonempty strings on Σ

A

Σ+

94
Q

A list of symbols from an alphabet

A

String

95
Q

An ordered n-tuple of elements of Σ, written without punctuation

A

String

96
Q

-> set of all strings over Σ of any finite length

A

Σ*

97
Q

there is a unique string of length zero over Σ called the and is denoted by ε

A

null string (empty string)

98
Q

Concatenation of two strings u, v ∈ Σ*

A

is the string uv obtained by joining the strings end-to-end

99
Q

The number of positions for symbols in the string. Denoted by |w|

A

Length of a String

100
Q

Let w = a1, a2, …, ak ∈ Σ*, where a1, a2, …, ak ∈ Σ. Then k is called the

A

length of the string:

101
Q

The string of zero length is called the _____. This is denoted by ε or λ

A

Empty String

102
Q

The string of zero length is called the empty string. This is denoted by

A

ε or λ

103
Q

The ______ plays the role of o in a number system

A

empty string

104
Q

If w = w1, w2, …, wn where w1 ∈ Σ, the reverse of w is wn, wn-1, … w1.

A

Reverse String

105
Q

If w = w1, w2, …, wn where w1 ∈ Σ, the _____ of w is wn, wn-1, … w1.

A

Reverse

106
Q

z is a _____ of w if z appears consecutively within w

A

Substring

107
Q

is the same as the dictionary ordering, except the shorter strings precede longer strings

A

Lexicographic ordering

108
Q

A set of strings from the same alphabet. Denoted by L(M).

A

Language

109
Q

The set of all strings, including the empty string over and alphabet Σ is denoted as Σ*
Infinite language L are denoted as:
L = {w ∈ Σ+: w has property P}

A

Language

110
Q

If L1 and L2 are languages over Σ, their concatenation is L = L1 * L2 or simply L = L1L2, where:

	L = {w ∈ Σ+ : w = x * y for some x ∈ L1 and y ∈ L2}
A

Concatenation of Language

111
Q

The set of all strings of a certain length from Σ

A

Powers of an Alphabet

112
Q

Denoted by Σk

A

Powers of an Alphabet

113
Q

The ______ is conventionally denoted by:

	Σ*=Σ0∪Σ1∪Σ2∪...
A

set of all strings over an alphabet Σ

114
Q

Its purpose is to remember the relevant portion of the system’s history.

A

State

115
Q

2 Types of State

A

Initial State
Final State

116
Q

Type of Conventions for Symbols and Strings

A

states -> q’s and p’s
qo -> initial state
0, 1, a, b -> input symbols
w, x, y, z -> strings of input symbols

117
Q

The basic structure of a proof is easy: it is just a series of statements, each one being either:

A

An assumption or
A conclusion, clearly following from an assumption or previously proved result.

118
Q

Proof Techniques:

A

Direct Proof
Proof by Contradiction
Proof by Contrapositive
If and Only if
Proof by Mathematical Induction

119
Q

Informally, a ____ that comprehensively captures all possible states and transitions that a machine can take while responding to a stream or sequence of input symbols

A

state diagram

120
Q

It consists of finite set of state and a set of transitions from state to state that occur on input symbols chosen from an alphabet

A

Finite Automata

121
Q

Used in text processors, compilers, and hardware design

A

Finite Automata

122
Q

Examples of Finite Automata:

A

Software for designing and checking the behavior of digital circuits
The compiler component that breaks the input text into logical units, such as identifiers, keywords, and punctuation
Software for scanning large bodies of text, such as collections of Web pages, to find occurrence of words, phrases, or other patterns.
Software for verifying systems of all types that have a finite number of distinct states, such as communications protocols or protocols for secure exchange of information

123
Q

Classes of Finite Automata

A

Deterministic Finite Automaton (DFA)
Nondeterministic Finite Automaton (NFA)

124
Q

The automaton cannot be in more than one state at any one time

A

Deterministic Finite Automaton (DFA)

125
Q

For each input symbol in Σ, there is exactly one transition of each state (possibly back to the state itself).

A

Deterministic Finite Automaton (DFA)

126
Q

It does not accept empty strings.

A

Deterministic Finite Automaton (DFA)

127
Q

The automaton may be in several states at once

A

Nondeterministic Finite Automaton (NFA)

128
Q

It allows zero, one, or more transitions for every input symbol

A

Nondeterministic Finite Automaton (NFA)

129
Q

It accepts empty strings

A

Nondeterministic Finite Automaton (NFA)

130
Q

Ways of Presenting Finite Automata

A

State Diagram (or Transition Graph)
State Table (or Transition Table)
Transition Function

131
Q

is a directed graph in that the vertices represent the internal states of the automaton, and the edges represent the transitions

A

transition graph

132
Q

The labels on the vertices are the names of the internal states, while the labels on the edge are the current values of the input symbols

A

transition graph

133
Q

The vertices of the graph correspond to the state of the FA

A

transition graph

134
Q

If there is a state q to p on input a, then there is an arc labeled “a” from state q to p

A

transition graph

135
Q

The FA accepts a string X if the sequence of transition corresponding to the symbols of X from the start state leads to an accepting state

A

transition graph

136
Q

δ (set of states, set of input alphabet)

A

Transition Function

137
Q

DFA is defined by the 5-tuple: {Q, ∑, δ, qo, F}

A

Formal Definition of a DFA

138
Q

a finite set of states

A

Q

139
Q

a finite set of input symbols (alphabet)

A

140
Q

a start state

A

q0

141
Q

set of final states

A

F

142
Q

a transition function, which is a mapping between Q x ∑ -> Q and takes as arguments a state and an input symbol and returns a state. (i.e., δ(qo, x) = q1)

A

δ

143
Q

Are those non final state which transits in itself for all input symbols

A

Dead State

144
Q

Is a real computer a DFA or a NFA?
It is a _____ because it has a definite or unique state that it goes through after receiving an input

A

DFA

145
Q

In order to write a program on ___, all possible scenarios for the alphabet and all possible transitions should be considered.
Hence knowledge of _____ is needed in order to write a program on ++++

A

DFA, NFA, DFA

146
Q

It is a ____ where there exist a nondeterminism for a given input symbol, which may lead to more than one state or may not go to any state, meaning, empty transition

A

Finite Automata

147
Q

Difference with NFA is that NFA is a ____ where the only difference from a DFA is the ______

A

5-tuple, concept of transition

148
Q

The ______ is the mapping of sets of states and the alphabet set to the power set.

A

NFDA transition function

149
Q

The _______ operates over a set of strings

A

NDFA transition

150
Q

To describe the behavior of M on w, we _____ the transition function δ to apply to a state and a string rather than a state and an input symbol

A

extend

151
Q

operates on a string of symbols

A

Extended Transition Function of NFA

152
Q

will be provided with a current state and an entire string of symbols, w.

A

Extended Transition Function of NFA

153
Q

Advantages and Caveats for NFA

A

Great for modeling regular expressions
String processing - e.g., grep, lexical analyzer
Could a non-deterministic state machine be implemented in practice?
A parallel computer could exist in multiple “states” at the same time
Probabilistic models could be viewed as extensions of non-deterministic state machines
(e.g., toss of a coin, a roll of dice)

154
Q

Some transitions could be non-deterministic. A transition could lead to a subset of states

A

NFA:

155
Q

Not all symbol transitions need to be defined explicitly (if undefined will go to a dead state - this is just a design convenience, not to be confused with “non-determinism”).

A

NFA:

156
Q

Accepts input if one of the last states in F

A

NFA:

157
Q

Generally easier than a DFA to construct

A

NFA:

158
Q

Practical implementation has to be deterministic (convert to DFA) or in the form of parallelism

A

NFA:

159
Q

All transitions are deterministic. Each transition leads to exactly one state

A

DFA:

160
Q

For each state, transition on all possible symbols (alphabet) should be defined

A

DFA:

161
Q

Accepts input if the last state is in F

A

DFA:

162
Q

Sometimes harder to construct because of the number of states

A

DFA:

163
Q

Practical implementation is feasible

A

DFA:

164
Q

But, DFAs and NFAs are ______ to capture languages

A

equivalent in their power

165
Q

The machine never really_____. It is always waiting for the next input symbol or making transitions.

A

terminates

166
Q

The machine decides when to _____ the next symbol from the input and when to _____ it. (but the machine can never ____ a symbol).

A

consume, ignore, skip

167
Q

A ____ can happen even without really consuming an input symbol (think of consuming ε as a free token).

A

transition

168
Q

A ______ cannot consume more than one symbol

A

single transition

169
Q

Allow explicit ε-transitions in finite automata i.e., a transition from one state to another state without consuming any additional input symbol.

A

NFA with Epsilon Transition

170
Q

Makes it easier sometimes to construct NFAs

A

NFA with Epsilon Transition

171
Q

are those NFAs with at least one explicit ε-transition defined.

A

ε-NFAs

172
Q

have one more column in their transition table

A

ε-NFAs

173
Q

Unlike NFA, ____with empty transitions can switch from one state to another without consuming an input symbol.

A

ε-NFAs

174
Q

Anything that can be represented with an εNFA can be represented with a _____

A

DFA that has no ε-transitions

175
Q

Before defining the transition function on a string
(δ (q,x) ), it is useful to first define what is known as the _____

A

ε closure

176
Q

Given a set of states S, the _____ will give the set of states reachable from each state in S using only ε transitions

A

ε closure

177
Q

is the set of all states (including itself) that can be reached from q by repeatedly making an arbitrary number of ε-transitions

A

ε-closure of a state q, ECLOSE(q)

178
Q

is a simple expression that describes the languages accepted by a FA

A

Regular Expressions

179
Q

Regular expressions are ____

A

very intuitive

180
Q

Regular expressions are very _____

A

useful in a variety of contexts

181
Q

Given a regular expression, an ______ can be constructed from it automatically, Thus, so can an NFA, a DFA, and a corresponding program, all automatically

A

NFA-e

182
Q

It is a sequence of characters that forms a search pattern, mainly for use in pattern matching with strings or string matching

A

Regular Expressions

183
Q

a or b

A

(a | b)

184
Q

zero or more occurrences of a or b

A

(a | b)*

185
Q

one or more occurrences of a or b

A

(a | b)^+

186
Q

all alphabets from a to z

A

[a-z]

187
Q

all alphabets from A to Z

A

[A-Z]

188
Q

countable set of all possible strings over a given alphabet

A

Language

189
Q

represents the empty set { }

A

Ø

190
Q

represents the set

A

ε

191
Q

represents the set {a}, for any symbol a in Σ
Let r and s be regular expressions that represent the sets R and S, respectively

A

a

192
Q

represents the set R U S

A

r+s

193
Q

represents the set RS

A

rs

194
Q

represents the set R*

A

r*

195
Q

represents the set R

A

(r)

196
Q

Operations Performed Over a Language

A

Union (R + S)
Concatenation (RS)
Kleene Star (R*)

197
Q

string is accepted by an ____ if there exists a path from the start state to a final state

A

eNFA

198
Q

Comparative study of regular expression, regular sets and finite automata

A

Thompson Construction