Automata Theory and Formal Language

Circuits in graphs are always simple paths.

• True
• False

What is a Universal TM?

• a TM that stimulates another TM
• A TM that can solve all problems
• A TM that can solve all undecidable problems
• a Universal TM does not exist

A right-most derivation of a sentential form is one in which rules transforming the are always applied.

• Context

A' will contain how many elements from the original set A?

{Q, Σ, q0, F, δ, Q × Σ → Q} is…

• An NFA
• Either DFA or NFA
• There is no such tuple
• A DFA

The minimum number of states required to recognize an octal number divisible by 3 are/is.

• 3

An order rooted tree that graphically represents the semantic information a string derived from a context-free grammar.

• Derivation tree

A finite number of states

• Q

The algebraic law of regular expression described by E + E = E is _____________.

• Annihilator
• Identity
• Additive idempotent
• Idempotent

The difference between regular expressions and finite automata is _____________.

• that automata are more program syntax-like while regular expression are more machine-like
• |regular expression| - |finite automata| = |Turing Machine| because you can only get the difference by computing for their respective lengths
• that regular expressions are more program syntax-like while automata are more machine-like
• {regular expression} - {finite automata} = { } because they are sets and they are equivalent

A set of rules, P: N → (N U T)*, it does have any right context or left context.

• P

A pushdown automaton is a way to implement a context-free grammar in a similar way to design DFA for a regular grammar.

• TRUE

A finite set of states.

• Q

An English like abbreviations representing elementary computer operations.

• Assembly Language

A DPDA is a PDA in which

• No state p has two outgoing transitions

T generate recursively enumerable languages. The productions have no restrictions and phase structure grammar including all formal grammars.

• Type-0 grammars

Any set that represents the value of the Regular Expression is called a Property set.

• FALSE

The stack contents

• s

Finite Automata all regular languages and only regular languages.

• Accept

The unconsumed input

• w

According to the 5-tuple representation i.e. FA= {Q, ∑, δ, q, F} Statement 1: q ϵ Q'; Statement 2: FϵQ

• Statement 1 is false, Statement 2 is true

A new symbol is added at the top.

• Push

Regular sets are closed under union,concatenation and kleene closure.

• TRUE

Given the productions S → αXβ, X → a, ___________________.

• X is not reachable nor generating
• X is reachable but not generating
• X is useful
• X is not reachable but is generating

A good regular expression for any valid whole number is ______________.

• [0-9]*
• [0-9]*[0-9]*
• [0-9]+
• [0-9]+[0-9]*

The relationship between recursive and recursively enumerable languages is ________________.

• ∈
• ⊂
• ∉
• ⊃

A _____ may or may not read an input symbol, but it has to read the top of the stack in every transition

• PDA

Which among the following is the correct option for the given grammar? G->X111|G1,X->X0|00.

• {0a1b|a=2,b=3}

The entity which generate Language is termed as:

• Grammar

A set on non-terminal symbols.

• S & A

A may or may not read an input symbol, but it has to read the top of the stack in every transition

• PDA

If L1 and L2 are regular sets then intersection of these two will be.

• Regular

Who is the father of modern computer?

• Charles Babbage

Turing hypothesis believed that a function is said to be computable if and only if it can be computed by a Turing machine.

• FALSE

Leibniz introduced binary notation of calculation.

• FALSE

Production Rule: aAb->agb belongs to which of the following category?

• Context Sensitive Language

A transition function: Q × (Σ∪{ε}) × S × Q × S*

• δ

A PDA machine configuration (p, w, y) can be correctly represented as.

• Current state, Unprocessed input, Stack content

The tape head is positioned at one of the tape cells for scanning the input symbol from the input tape and initially the tape head points at the left most cell of the input tape.

• TRUE

One of the first programmable electronic computers in 1945.

• ENIAC

The difference between DFA and NFA

• DFA is where you get your passport while NFA is where you get your cheap rice
• NFA can exist in only one state at a given time while DFA can exist in multiple states
• DFA can exist in only one state at a given time while NFA can exist in multiple states
• DFA is also an NFA

An automaton that produces outputs based on current input and/or previous state is called.

• Transducer

Is the transition function where δ: Q × Σ → Q.

• δ

Identify the modeling recognition of the word "then"

• Start State

__ is the transition function where δ: Q × Σ → Q.

• δ

In _____ Allan M. Turing proposed the Turing machine as a model of "any possible computation".

• 1936

An ε-NFA with a stack is also regarded as:

• A CFG
• A FSA
• A PDA
• A RE

What cannot be said about automata theory?

• None of the choices
• Automata theory is the study of abstract computing devices or machines
• Automata theory is used to find out if a problem is computable
• Automata theory answers the fundamental questions in computer science

A set of final state/states of Q (F⊆Q).

• F

It is a unary operator on a set of symbols or strings, that gives the infinite set of all possible strings of all possible lengths.

• Σ *

An indirect way of building a CFG is to _____________

• build a regular expression and then construct a PDA from it, and then construct CDF from it
• You can only build a CFG directly
• build a PDA and then construct a CFG from it
• none of the given choices

The power set of a given set does not contain the set itself.

• True
• False

Checking whether there is a matching parenthesis in a computer code can be done by a ______________.

• regular expression
• automatically by a very patient debugger
• context-free language
• context-free grammar

A nested if-then statement is one of these:

• If w then x if y then z
• If w if x then y then z
• If w then if x then y else z
• All of the choices are examples of nestedness

Recursive : TM that always halt = ________________ : TM that may or may not halt

• iterative
• recursively enumerable
• none of the choices given
• iteratively enumerable

The complement of an infinite language is necessarily finite.

• FALSE

“If H then ” is also the same as saying _______.

• “If H then C else do nothing”
• “If C then H”
• “If H then C else {}”
• “C if H”

Labeled by a non-terminal symbol.

• Vertex

Context-free grammars are more expressive than finite automata; if a language L is _____ by a finite automata then L can be _______ by a context-free grammar.

• accepted, generated

NP-Hard problems are problems that are...

• Easy (they are called hard so that computer programmers can be paid more)
• intractable
• none of the choices
• hard

A regular expression consisting of a finite set of grammar rules is a quadruple.

• FALSE

A general purpose, programmable, information processor with input and output.

• computer

The __________ of a Turing machine depends on the current state of finite control and the tape symbol present in the input tape.

• single move

Who is the father of modern computer science?

• Noam Chomsky
• Alan Turing
• Steve Jobs
• Bill Gates

Given that the language L = {ε}, is L empty?

• None of the given choices
• No, because the language has an empty symbol
• Definitely, because ε is an empty symbol
• This is a case of apples and oranges, you really can't compare!

What are strings?

• A string is an infinite area of symbols chosen from Σ
• A string is a finite sequence of symbols chosen from Σ
• A string is a finite area of symbols chosen from Σ
• A string is an infinite sequence of symbols chosen from Σ

Is a finite set of symbols called the alphabet.

• Σ

Every set is a / an ________________ of itself.

• None of the choices
• Complement
• Proper Subset
• Improper Subset

What is a language?

• A way to communicate with other humans
• A collection of finite-length sentences that were constructed from a finite set of symbols
• A code that you use when writing a computer program
• English, Filipino and Valyrian are examples of a language

The body of a production in CFG is composed of:

• a string of terminals only
• none of the choices given because a CFG production does not have a body
• a string of non-terminals only
• a string of terminals and non-terminals

Any production rule in the form A → B where A, B ∈ Non-terminal is called.

• Unit Production

The cardinality of the union of two disjoint sets is less than the sum of the cardinality of the given sets.

• True
• False

Labeled by the start symbol.

• Root Vertex

For every CFL, G, there exists a PDA M such that L(G) = L(M) and vice versa.

• TRUE

If we can successfully and correctly stimulate a TM with storage by two standard TMs, then ______________________.

• None of the choices
• we have already shown that the TM with storage is at least twice as powerful as one standard TM
• we have already shown that the two are equivalent
• we have already shown that one standard TM is half as powerful as the TM with storage

What is an undecidable problem?

• When a TM cannot make a decision on an instance of the problem
• When a CFG cannot make a decision on an instance of the problem
• When a PDA cannot make a decision on an instance of the problem
• When a RE cannot make a decision on an instance of the problem

The transition a Push down automaton makes it additionally dependent upon the _____.

• stack

A set of strings of a's and b's of any length including the null string. So L= { ε, a, b, aa , ab , bb , ba, aaa.......}, the regular expression is.

• (a+b)*

It refers to the measure of the number of times the tape moves when the machine is initialized for some input symbols and the space complexity is the number of cells of the tape written.

• Time Complexity

It generate context-free languages. The productions must be in the form A → γ

• Type-2 grammars

Context-free grammars are more expressive than finite automata; if a language L is by a finite automata then L can be by a context-free grammar.

• Accepted, Ignored

* Starts from tree leaves. It proceeds upward to the root which is the starting symbol S

• bottom-up approach

Is used to derive a string using the production rules of a grammar.

• Production

An initial state q0 ∈ Q

• q0

According to what concept is CFL a superset of RL?

• Chomsky Hierarchy
• Chomsky Normal Form
• Backus-Naur Form
• None of the given choices

A transition function δ : Q × (Σ ∪ {ε}) → 2Q.

• δ

Is the initial state from where any input is processed (q0 ∈ Q).

• q0

A stack symbols

• Σ

Transition function

• δ

The number of elements in the set for the Language L={xϵ(∑r) *|length if x is at most 2} and ∑={0,1} is

• 7

Elimination of productions and symbols is called simplification of CFGs. Simplification essentially comprises of the following steps:

• Reduction of CFG

A pushdown automata can be regarded as:

• a ε-NFA with a stack
• a DFA with a FILO queue
• a NFA with a stack
• a DFA with FIFO queue

A string is accepted by a, iff the DFA/NDFA starting at the initial state ends in an after reading the string.

• NDFA

All functions are relations

• True
• False

The stack contents.

• s

Some graphs contain cycles.

• True
• False

What is an ε-NFA?

• It is a DFA where all transitions are ε-transitions
• It is an NFA where all transitions are ε-transitions
• It is a DFA with at least one explicit ε-transition defined
• It is an NFA with at least one explicit ε-transition defined

The basic model of a Turing machine consists of _______ and _______ , in which the finite control has finite set of states and the transition between the states.

• finite control, input tape

A good regular expression for any valid real number using engineering notation is ______________.

• [0-9]+[0-9]*[(E|e)[0-9]+]
• [0-9]*
• [0-9]+[0-9]*[(E|e|∈)[0-9]+]
• [0-9]+

How many rational and irrational numbers are possible between 0 and 1?

• 0
• Infinite
• Finite
• 1

A good regular expression of a person's name is ______________.

• None of the given choices
• [A-Z][a-z]+
• [A-Z][a-z]?
• [A-Z][a-z]*

* Starts with the starting symbol S. It goes down to tree leaves using productions.

• Top-Down Approach

If L is recursively enumerable then ________________.

• none of the choices given is correct
• L is also recursively enumerable
• L is definitely not recursively enumerable
• L may not be recursively enumerable

“C if H” is also the same as saying _______.

• “If H then ”
• “If C then H”
• “If H then C else {}”
• “If H then C else do nothing”

In the Chomsky Hierarchy:

• Regular Language ⊂ Context-sensitive Language
• Regular Language ⊃ Context-sensitive Language
• Regular Language| • |Context-sensitive Language
• Regular Language = Context-sensitive Language

What can be said about undecidable problems?

• They are definitely recursive
• They are surely iterative
• They are not recursive
• They are not iterative

Having the initial state as a final state, give the deterministic finite state automaton that accepts the regular expression.

• ((a.b)+c)*

Noam Chomsky gave a mathematical model in ___ which is effective for writing computer languages.

• 1956

A set of terminals where N ∩ T = NULL.

• T

Which of the following statements are for a concept called inherent ambiguity in CFL?

• Every CFG for L is ambiguous

Context-free grammars are more expressive than finite automata; if a language L is by a finite automata then L can be blank by a context-free grammar.

• Accepted

NFA means:

• Nondeterministic Finite Automaton
• Nondeterministic Final Automaton
• Nondifferentiable Final Automaton
• Nondifferential Finite Automaton

The initial stack top symbol (I ∈ S)

• I

Computers are general purpose because they can perform many different tasks.

• TRUE

The initial stack top symbol (I ∈ S).

• I

A set has n elements, then the number of elements in its power set is?

• 2n
• 2 ^ n
• None of the choices
• 2n-1

__ is the initial state from where any input is processed (q0 ∈ Q).

• q0

An algorithms to shampoo your hair.

• rinse, lather, repeat

A PDA accepts a string when, after reading the entire string, the PDA is in a final state.

• TRUE

The string "0000111" is accepted by _____________.

• the CFG S → 0S1 | A, A → A1 | ε
• the CFG S → 1S0 | A, A → A0 | ε
• the CFG S → 0S1 | A, A → 0A | ε
• none of the choices

The union of sets A and B is expressed as?

• A U B
• A - B
• A / B
• A x B

If a problem can be shown that it belongs to the class of recursively enumerable languages then ______________________.

• It may be solved by any TM
• It may be solved by a special RE
• It may be solved by a special TM
• It may be solved by any RE

What can be said about CFLs?

• It is closed under ~
• It is closed under ∩
• All of the given choices
• It is closed under •

A finite set of input symbols.

• Σ

Which among the following cannot be accepted by a regular grammar?

• L is a set of 0n1n

* Starts from tree leaves. It proceeds upward to the root which is the starting symbol S.

• Bottom-Up Approach

Which of the following statements are correct for a concept called inherent ambiguity in CFL?

• Every CFG for L is ambiguous

A DFA is defined ____________________.

• as Department of Finite Automaton
• by a 5-tuple which is {Q, Σ, q0, F, δ}
• by a 6-tuple which is {Q, Σ, q0, F, δ, Q × Σ → Q}
• as Department of Foreign Affairs

A finite set of states

• Q

A symbol X is reachable _________________________.

• if S → aXβ
• if X →* w, for some w ∈ Σ
• if X → w, for some w ∈ Σ
• if S →* aXβ

For bottom-up parsing, a PDA has the following four types of transitions:

• Push the current input symbol into the stack., Replace the right‑hand side of a production at the top of the stack with its left‑hand side. , If the top of the stack element matches with the current input symbol, pop it. , If the input string is fully read and only if the start symbol 'S' remains in the stack, pop it and go to the final state .

The start symbol.

• S

Computer science has roots in two fields :

• Mathematics

For a regular expression 'a', we can construct the following FA:

• TRUE

The algebraic law of regular expression described by φE = φ = Eφ is _______________.

• Annihilator
• Associative
• Commutative
• Identity

are parameterized statement, they are true or false depending on the values of their parameters.

• predicates

What is the final result after converting the following NFA-ε to NFA without Null move.

• What is the final result after converting the following NFA-ε to NFA without Null move.

Start symbol, S ∈ N

• S

For every pair of regular expressions R and S, the languages denoted by R(SR)* and (RS)*R are the same.

• TRUE

The string acde is accepted by this regular expression.

• a+b+c+d+
• a+b+c+d+e*
• a*b*c*a*d*
• a*b*c*a*d*e+

Starting state

• q0

If A = {3, 4, 6, 8} and

• { 4,6}

There are 5 tuples in finite state machine.

• TRUE

The unconsumed input.

• w

Global Positioning System (GPS) calculates latitude and longitude from satellite signals.

• True

|-* is the _____ closure of |-

• transitive and reflexive

|-* is the closure of |-

• Transitive and Reflexive

Are ambiguous grammar context free?

• TRUE

A PDA machine configuration (p, w, y) can be ly represented as ____________

• current state, unprocessed input, stack content

A DFA can remember a finite amount of information, but a ____ can remember an infinite amount of information.

• PDA

If we can successfully and ly stimulate a TM with storage by two standard TMs, then ______________________

• we have already shown that the two are equivalent

It starts from the bottom with the string and comes to the start symbol using a parse tree.

• Bottom-Up Parser

The CFG "S → (S) | SS | ε" accepts:

• the string "<<>><><<>>"
• the string "(((((((((())))))))))"
• the string "((()))(())(())"
• the string "{} { {} } [[]]"

Connected graphs have components.

• True
• False

A grammar G is ambiguous if there is a word w Î L(G) having are least two different parse trees.

• TRUE

In words, H → C means…

• Whenever H holds, C follows
• Whenever H does not follow, C does not follow either
• Whenever H is true, then it becomes C
• Whenever H, then it becomes C

______ is used to derive a string using the production rules of a grammar.

• Parsing

IT generate recursively enumerable languages. The productions have no restrictions and phase structure grammar including all formal grammars.

• Type-0 grammars

Which of the following statements is true about NPDA, DPDA, and RL?

• RL • DPDA • NPDA
• RL* • DPDA* • NPDA*
• RL ⊃ DPDA ⊃ NPDA
• RL ⊂ DPDA ⊂ NPDA

Context Free Languages is closed under intersection.

• False
• True

If A has m elements and B has n elements, then A x B has elements?

• m - n
• m + n
• 2n
• m x n

Finite set of input alphabets

• Σ

If R = {(1,1),(2,3),(4,5)}, then domain of the function is?

• Dom R = {2,3,4,5}
• Dom R = {1,2,4}
• Dom R {1,3,5}
• Dom R {1,1,4,5}

S → aAb, aA →aaAb, A→ε

• P

If A = {0,2) and B = {1,3), then Cartesian product is?

• none of the choices
• A x B not equal B x A
• A x B = B x A
• is not possible

Unconsumed input

• w

Regular expression Φ* is equivalent to.

• ϵ

The of a Turing machine depends on the current state of finite control and the tape symbol present in the input tape.

• Single Move

Increasing coverage, or recall.

• Minimizing False Negatives

Unconsumed input.

• w

If R ={(1,1),(2,3),(4,5)}, then the Range of the function is?

• Range R {1,1,4,5}
• Range R {1,2,5}
• Range R = {2,3,4,5}
• Range R = {1,3,5}

A set of accepting states (F ∈ Q).

• F

Noam Chomsky gave a mathematical model in which is effective for writing computer languages.

• 1956

A DPDA is a PDA in which.

• No state p has two outgoing transitions

The string aaaabbbccaaad is accepted by this regular expression.

• a+b+c+d+
• a*b*c*a*d*e+
• a*b*c*a*d*
• a+b+c+d+e*

__ is a set of final state/states of Q (F ⊆ Q).

• F

A Moore machine can be described by a tuple.

• 6

A conceptual design for a machine consisting of a Mill, Store, Printer, and Readers.

• Analytic Engine

Regular expression Φ* is equivalent to

• ϵ

Let the class of language accepted by finite state machine be L1 and the class of languages represented by regular expressions be L2 then.

• L1=L2

Which of the following statement is false in context of tree terminology?

• Root with no children is called a leaf

The first mechanical calculator using gears for calculation developed in 1642.

• Pascaline

How many sets belong to the power set of A = {a,b,c,d}?

• 4
• 8
• 7
• 16

If L1 and L2 are regular sets then intersection of these two will be

• Regular

Which of the following is a not a part of 5-tuple finite automata?

• Output Alphabet

The stack content

• s

What can not be said about CFLs?

• It is closed under ~
• It is closed under —
• All of the given choices
• It is closed under ∩

A transition function: Q × (Σ∪{ε}) × S × Q × S*.

• δ

A set of strings of a's and b's of any length including the null string. So L= { ε, a, b, aa , ab , bb , ba, aaa.......}, the regular

• (a+b)*

Increasing accuracy, or precision

• Minimizing False Positives

Which of the following ways can be done to simplify a CFG?

• Eliminate symbols that are not useful
• Eliminate the ε symbol
• Eliminate productions of the form A → B

A sub-tree of a derivation tree/parse tree such that either all of its children are in the sub-tree or none of them are in the

• Partial Derivation Tree, Sub-Tree

A PDA machine configuration (p, w, y) can be correctly represented as ____________ .

• current state, unprocessed input, stack content

A language accepted by Deterministic Push down automata is closed under which of the following?

• complement

Which one is the answer?

• Computer

Set of all tape symbols

• Γ

Number of final state require to accept in minimal finite automata.

• None of the mentioned

Finite set of input alphabets.

• Σ

The _____ of two sets A and B is the set containing those elements which are elements of A or elements of B.

• union

Set of final or accepting states.

• F

All trees contain loops.

• True
• False

Every context free grammar can be transformed into an equvalent non deterministic push down automata.

• TRUE

Increasing accuracy, or precision.

• Minimizing False Positives

Is to be applied to show that certain languages are not regular. It should never be used to show a language is regular.

• Pumping Lemma

All relations are functions

• True
• False

Any production rule in the form A → B where A, B ∈ Non-terminal is called unit production.

• Unit Production

For the given Regular expression, the minimum number of terminals required to derive its grammar (011+1)*(01)* is

• 3,6,2,5,4

Noam Chomsky gave a mathematical model in _______ which is effective for writing computer languages.

• 1956

Which of the following will not be accepted by the following DFA?

• ababaabaa

A parsing that starts from the top with the start-symbol and derives a string using a parsetree.

• top-down parser

Empty set is a/an ________________.

• Infinite set
• Finite set
• Invalid set
• None of the choices

A Finite Automaton with null moves (FA-ε) does transit not only after giving input from the alphabet set but also without any input symbol. This transition without input is called a.

• Null Move

What is a grammar?

• How a sentence should be constructed to avoid syntax error
• "Them cowboys is dumb!" is an example of a wrong grammar
• "We ain't gonna make mistakes" is an example of correct grammar
• A device that enumerates the sentences of a language

Set of final or accepting states

• F

The transition a Push down automaton makes it additionally dependent upon the

• Stack

JASON can generally be parsed by ______________.

• A C parser
• A CFG
• A Java parser
• A RE

Terminal symbols

• a & b

Which among the following is the option for the given grammar? G->X111|G1,X->X0|00

• {0a1b|a=2,b=3}

Labeled by a terminal symbol or ε.

• Leaves

A PDA is already in its accept state if:

• and only if it is both in the final state and the stack is empty
• none of the given choices
• it is either in the final state or the stack is empty
• it has no more input to process

The first counting machine developed 5000 years ago in the Middle East.

• Abacus

In mathematical notation, the symbol → means...

• implication
• an element of
• not an element of
• assignment statement

What kind of languages does a TM decide?

• regular expression
• context-sensitive
• recursively enumerable
• context-free

A of a derivation is a tree in which each internal node is labeled with a nonterminal.

• Parse Tree

Empty string

• Σ

The empty set is always a subset of any set.

• True
• False

If A →* ε, then we can say that:

• A is not generating
• A is not reachable
• A is nullable
• A is not generally useful

Is a finite set of states.

• Q

Is a set of final state/states of Q (F ⊆ Q).

• F

A formal language is a set of strings, each string composed of symbols from a finite set called

• alphabet

Non-terminal symbols

• S & A

The initial state (q0 ∈ Q)

• q0

A DFA can remember a finite amount of information, but a can remember an infinite amount of information.

• PDA

If A = {5,6,7} and B = {7,8,9} then A U B is equal to:

• {5,6,7}
• None of the choices
• {7,8,9}
• {5,6,7,8,9}

Finite set of states

• Q

A __________ of a derivation is a tree in which each internal node is labeled with a nonterminal.

• parse tree

Z2 uses electricity to convey letters and transmit information quickly in 1844.

• TRUE

A language is regular if and only if.

• Accepted by DFA

The theory of formal languages finds its applicability extensively in the fields of Computer Science. gave a mathematical model of grammar in which is effective for writing computer languages.

• Noam Chomsky, 1956

Number of states require to accept string ends with 10.

• 3

What concept did Alan Turing introduce?

• The concept of programs and programmabilities of problems
• The concept of decidability
• The concept of functions and relations
• The concept of undecidability

In Allan M. Turing proposed the Turing machine as a model of "any possible computation".

• 1936

The top symbol is read and removed.

• Pop

Let w = 100011, is w a member of a language of string with equal number of 0s and 1s?

• Yes, because the number of 1s is the same as the number of 0s, which is 3
• It is hard to ascertain because 100011 is 35 in decimal, which is an odd number
• No, because even if the symbols 1 and 0 are of the same number, they are not palindromic
• This is an NP-hard problem

The following are phases of C++ Programs except

• Process

An example string w of a language L characterized by equal number of As and Bs is _______________.

• BABAE
• ABABA
• ABBBAA
• ALIBABA

An alphabet is any finite set of symbols.

• TRUE

The intersection of sets A and B is expressed as _________________.

• A - B
• A / B
• A x B
• A ∩ B

The string abe is accepted by this regular expression.

• a*b*c*a*d*
• a+b+c+d+e*
• a*b*c*a*d*e+
• a+b+c+d+

A - B will contain elements in?

• B not in A
• A not in B
• Neither A nor B
• Both A and B

A compact textual representation of a set of strings representing a language.

• Regular Expressions

It starts from the top with the start-symbol and derives a string using a parse tree.

• Top-Down Parser

Which among the following is not a part of the Context free grammar tuple?

• End SymbolCorre

A DFA is represented by digraphs called.

• State Diagram

Blank symbol

• Δ

The entity which generate Language is termed as regular languages.

• FALSE

What is automata theory?

• To answer the fundamental questions in computer science
• All of the choices
• To find out if a problem is computable
• Study of abstract computing devices or machines

__ is a finite set of symbols called the alphabet.

• Σ

A finite number of states.

• Q

A ⊂ B is read as ________________.

• A is less than B
• A is a subset of B
• B is a subset of A
• A is a proper subset of B

Which of the following Set Operations produces the set that contains everything that is in Set A and in Set B?

• Complement
• union
• Intersection
• Set Difference

A 2-Tape Turing Machine ___________________.

• can infer that recursive languages are closed under union
• can show that recursive languages are closed under union
• has two outputs
• has two inputs

A Finite Automaton with null moves (FA-ε) does transit not only after giving input from the alphabet set but also without any input symbol. This transition without input is called a

• Null Move

If Σ2 is {00, 01, 10, 11}, then Σ =

• {0, 1}
• {false, true}
• {true, false}
• {F, T}

The recursive inference procedure determines that string w is in the language of the variable A, A being the starting variable.

• TRUE

The language L contains all strings over the alphabet {a,b} that begin with and end with

• a,b

The symbol used for the empty string is ____________.

• ε
• φ
• a blank
• ψ

A formal language is a set of strings, each string composed of symbols from a finite set called.

• Alphabet

“Whenever H holds, C follows” can also be said as _______.

• H → ε and ε → C
• H → C
• C → H
• ε → H and C → ε

For every CFL, G, there exists a PDA M such that L(G) = L(M) and vice versa

• TRUE

Given the language L = {ε}, is L empty?

• none of the given choices
• Definitely, because ε is an empty symbol
• No, because the language has an empty symbol
• You can't say

A set of accepting states (F ∈ Q)

• F

It process information in their efforts to eat, survive, and reproduce.

• Living Organisms

challenged the mathematical community to find an infallible, mechanical method for constructing and checking truth of mathematical statements.

• David Hilbert

__ is a finite set of states.

• Q

The commutativity property of set operations states that the union of any set with same set is the set itself.

• True
• False

IT generate recursively enumerable languages. The productions have no restrictions and phase structure grammar including all formal grammars. They generate the languages that are recognized by a Turing machine.

• Type-0 grammars

Language may be derived from other strings using the productions in a grammar.

• FALSE

A may or may not read an input symbol, but it has to read the top of the stack in every transition.

• PDA

In ____ Allan M. Turing proposed the Turing machine as a model of "any possible computation".

• 1936

An initial state q0 ∈ Q.

• q0

Finite set of states.

• Q

The PDA has infinite memory and access in _____ order and the finite automata has ____ memory.

• LIFO, finite