Automata Theory and Formal Language

The course introduces some fundamental concepts in automata theory and formal languages including grammar, finite automaton, regular expression, formal language, pushdown automaton, and Turing machine. Not only do they form basic models of computation, they are also the foundation of many branches of computer science, e.g. compilers, software engineering, concurrent systems, etc. The properties of these models will be studied and various rigorous techniques for analyzing and comparing them will be discussed, by using both formalism and examples.

QUESTIONS	ANSWERS
TRUE	An alphabet is any finite set of symbols.
Leaves	Labeled by a terminal symbol or ε.
S & A	Non-terminal symbols
Type-0 grammars	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.
w	Unconsumed input.
Accept	Finite Automata all regular languages and only regular languages.
TRUE	Z2 uses electricity to convey letters and transmit information quickly in 1844.
P	S → aAb, aA →aaAb, A→ε
alphabet	A formal language is a set of strings, each string composed of symbols from a finite set called
((a.b)+c)*	Having the initial state as a final state, give the deterministic finite state automaton that accepts the regular expression.
1956	Noam Chomsky gave a mathematical model in ___ which is effective for writing computer languages.
F	A set of accepting states (F ∈ Q)
F	Set of final or accepting states
Assembly Language	An English like abbreviations representing elementary computer operations.
Parse Tree	A of a derivation is a tree in which each internal node is labeled with a nonterminal.
union	The _____ of two sets A and B is the set containing those elements which are elements of A or elements of B.
No state p has two outgoing transitions	A DPDA is a PDA in which.
Regular	If L1 and L2 are regular sets then intersection of these two will be
Parse Tree	An order rooted tree that graphically represents the semantic information a string derived from a context-free grammar.
FALSE	Turing hypothesis believed that a function is said to be computable if and only if it can be computed by a Turing machine.
δ	A transition function: Q × (Σ∪{ε}) × S × Q × S*
F	A set of accepting states (F ∈ Q).
S	The start symbol.
Answer	QUESTIONS
NDFA	A string is accepted by a, iff the DFA/NDFA starting at the initial state ends in an after reading the string.
w	The unconsumed input
accepted, generated	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.
Derivation tree	An order rooted tree that graphically represents the semantic information a string derived from a context-free grammar.
Type-0 grammars	IT generate recursively enumerable languages. The productions have no restrictions and phase structure grammar including all formal grammars.
Type-2 grammars	It generate context-free languages. The productions must be in the form A → γ
TRUE	Are ambiguous grammar context free?
a,b	The language L contains all strings over the alphabet {a,b} that begin with and end with
Minimizing False Positive	Increasing accuracy, or precision.
ϵ	Regular expression Φ* is equivalent to
computer	A general purpose, programmable, information processor with input and output.
Σ	Is a finite set of symbols called the alphabet.
current state, unprocessed input, stack content	A PDA machine configuration (p, w, y) can be correctly represented as ____________ .
S	Start symbol, S ∈ N
3	Number of states require to accept string ends with 10.
TRUE	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.
bottom-up approach	* Starts from tree leaves. It proceeds upward to the root which is the starting symbol S
Noam Chomsky, 1956	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.
{0a1b|a=2,b=3}	Which among the following is the correct option for the given grammar? G->X111|G1,X->X0|00.
Process	The following are phases of C++ Programs except
Regular Expressions	A compact textual representation of a set of strings representing a language.
top-down parser	A parsing that starts from the top with the start-symbol and derives a string using a parsetree.
Regular	If L1 and L2 are regular sets then intersection of these two will be.
ENIAC	One of the first programmable electronic computers in 1945.
Parsing	Is used to derive a string using the production rules of a grammar.
PDA	A _____ may or may not read an input symbol, but it has to read the top of the stack in every transition
1936	In _____ Allan M. Turing proposed the Turing machine as a model of "any possible computation".
δ	__ is the transition function where δ: Q × Σ → Q.
Q	A finite number of states
Single Move	The of a Turing machine depends on the current state of finite control and the tape symbol present in the input tape.
Output Alphabet	Which of the following is a not a part of 5-tuple finite automata?
Accepted by DFA	A language is regular if and only if.
I	The initial stack top symbol (I ∈ S)
Minimizing False Negative	Increasing coverage, or recall.
Computer	Which one is the answer?
TRUE	For every pair of regular expressions R and S, the languages denoted by R(SR)* and (RS)*R are the same.
L1=L2	Let the class of language accepted by finite state machine be L1 and the class of languages represented by regular expressions be L2 then.
q0	An initial state q0 ∈ Q.
Reduction of CFG	Elimination of productions and symbols is called simplification of CFGs. Simplification essentially comprises of the following steps:
Null Move	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.
rinse, lather, repeat	An algorithms to shampoo your hair.
s	The stack contents.
F	Set of final or accepting states.
Q	Finite set of states.
(a+b)*	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
q0	An initial state q0 ∈ Q
Living Organisms	It process information in their efforts to eat, survive, and reproduce.
Transducer	An automaton that produces outputs based on current input and/or previous state is called.
State Diagram	A DFA is represented by digraphs called.
LIFO, finite	The PDA has infinite memory and access in _____ order and the finite automata has ____ memory.
Σ	A finite set of input symbols.
A	What is the final result after converting the following NFA-ε to NFA without Null move.
q	The state.
Partial Derivation Tree, Sub-Tree	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
q0	Starting state
ϵ	Regular expression Φ* is equivalent to.
No state p has two outgoing transitions	A DPDA is a PDA in which
Q	A finite set of states.
TRUE	For a regular expression 'a', we can construct the following FA:
TRUE	A grammar G is ambiguous if there is a word w Î L(G) having are least two different parse trees.
F	__ is a set of final state/states of Q (F ⊆ Q).
Bottom-Up Approach	* Starts from tree leaves. It proceeds upward to the root which is the starting symbol S.
1936	In ____ Allan M. Turing proposed the Turing machine as a model of "any possible computation".
F	A set of final state/states of Q (F⊆Q).
T	A set of terminals where N ∩ T = NULL.
1936	In Allan M. Turing proposed the Turing machine as a model of "any possible computation".
What is the final result after converting the following NFA-ε to NFA without Null move.
I	The initial stack top symbol (I ∈ S).
Q	Is a finite set of states.
PDA	A may or may not read an input symbol, but it has to read the top of the stack in every transition
Σ	Finite set of input alphabets
Charles Babbage	Who is the father of modern computer?
Alphabet	A formal language is a set of strings, each string composed of symbols from a finite set called.
Time Complexity	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.
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 .	For bottom-up parsing, a PDA has the following four types of transitions:
s	The stack contents
TRUE	There are 5 tuples in finite state machine.
δ	A transition function δ : Q × (Σ ∪ {ε}) → 2Q.
ababaabaa	Which of the following will not be accepted by the following DFA?
w	The unconsumed input.
Transitive and Reflexive	|-* is the closure of |-
3	The minimum number of states required to recognize an octal number divisible by 3 are/is.
N	A set on non-terminal symbols.
Stack	The transition a Push down automaton makes it additionally dependent upon the
q	The state
w	Unconsumed input
Top-Down Approach	* Starts with the starting symbol S. It goes down to tree leaves using productions.
Current state, Unprocessed input, Stack content	A PDA machine configuration (p, w, y) can be correctly represented as.
Grammar	The entity which generate Language is termed as:
TRUE	A PDA accepts a string when, after reading the entire string, the PDA is in a final state.
Analytic Engine	A conceptual design for a machine consisting of a Mill, Store, Printer, and Readers.
Mathematics	Computer science has roots in two fields :
Vertex	Labeled by a non-terminal symbol.
finite control, input tape	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.
Σ	Empty string
Σ *	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.
End Symbol	Which among the following is not a part of the Context free grammar tuple?
transitive and reflexive	|-* is the _____ closure of |-
FALSE	A regular expression consisting of a finite set of grammar rules is a quadruple.
Q	__ is a finite set of states.
TRUE	For every CFL, G, there exists a PDA M such that L(G) = L(M) and vice versa
Σ	A stack symbols
Γ	Set of all tape symbols
Accepted	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.
δ	Transition function
q0	Is the initial state from where any input is processed (q0 ∈ Q).
(a+b)*	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.
None of the mentioned	Number of final state require to accept in minimal finite automata.
q0	__ is the initial state from where any input is processed (q0 ∈ Q).
Start State	Identify the modeling recognition of the word "then"
Δ	Blank symbol
L is a set of 0n1n	Which among the following cannot be accepted by a regular grammar?
single move	The __________ of a Turing machine depends on the current state of finite control and the tape symbol present in the input tape.
TRUE	For every CFL, G, there exists a PDA M such that L(G) = L(M) and vice versa.
Alan Turing	Who is the father of modern computer science?
FALSE	Any set that represents the value of the Regular Expression is called a Property set.
{3,6}	If A = {3, 4, 6, 8} and
Type-0 grammars	T generate recursively enumerable languages. The productions have no restrictions and phase structure grammar including all formal grammars.
Q	A finite number of states.
Accepted, Ignored	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.
TRUE	The recursive inference procedure determines that string w is in the language of the variable A, A being the starting variable.
Abacus	The first counting machine developed 5000 years ago in the Middle East.
Context Sensitive Language	Production Rule: aAb->agb belongs to which of the following category?
Bottom-Up Parser	It starts from the bottom with the string and comes to the start symbol using a parse tree.
predicates	are parameterized statement, they are true or false depending on the values of their parameters.
Parsing	______ is used to derive a string using the production rules of a grammar.
q0	The initial state (q0 ∈ Q)
TRUE	Every context free grammar can be transformed into an equvalent non deterministic push down automata.
complement	A language accepted by Deterministic Push down automata is closed under which of the following?
Root Vertex	Labeled by the start symbol.
Pumping Lemma	Is to be applied to show that certain languages are not regular. It should never be used to show a language is regular.
6	A Moore machine can be described by a tuple.
Push the current input symbol into the stack.	For bottom-up parsing, a PDA has the following four types of transitions:
FALSE	Leibniz introduced binary notation of calculation.
a & b	Terminal symbols
David Hilbert	challenged the mathematical community to find an infallible, mechanical method for constructing and checking truth of mathematical statements.
3,6,2,5,4	For the given Regular expression, the minimum number of terminals required to derive its grammar (011+1)*(01)* is
Null Move	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
δ	Is the transition function where δ: Q × Σ → Q.
Minimizing False Negatives	Increasing coverage, or recall.
Q	Finite set of states
Σ	Finite set of input alphabets.
Root with no children is called a leaf	Which of the following statement is false in context of tree terminology?
Push	A new symbol is added at the top.
PDA	A DFA can remember a finite amount of information, but a ____ can remember an infinite amount of information.
1956	Noam Chomsky gave a mathematical model in which is effective for writing computer languages.
Every CFG for L is ambiguous	Which of the following statements are correct for a concept called inherent ambiguity in CFL?
TRUE	Any production rule in the form A → B where A, B ∈ Non-terminal is called unit production.
TRUE	Regular sets are closed under union,concatenation and kleene closure.
Minimizing False Positives	Increasing accuracy, or precision.
Unit Production	Any production rule in the form A → B where A, B ∈ Non-terminal is called.
PDA	A DFA can remember a finite amount of information, but a can remember an infinite amount of information.
Production	Is used to derive a string using the production rules of a grammar.
Q	A finite set of states
FALSE	The entity which generate Language is termed as regular languages.
TRUE	A pushdown automaton is a way to implement a context-free grammar in a similar way to design DFA for a regular grammar.
Pop	The top symbol is read and removed.
Minimizing False Positives	Increasing accuracy, or precision
Top-Down Parser	It starts from the top with the start-symbol and derives a string using a parse tree.
Go to bathroom	An algorithms to shampoo your hair.
TRUE	Computers are general purpose because they can perform many different tasks.
Σ	__ is a finite set of symbols called the alphabet.
FALSE	The complement of an infinite language is necessarily finite.
F	Is a set of final state/states of Q (F ⊆ Q).
Context	A right-most derivation of a sentential form is one in which rules transforming the are always applied.
P	A set of rules, P: N → (N U T)*, it does have any right context or left context.
δ	A transition function: Q × (Σ∪{ε}) × S × Q × S*.
PDA	A may or may not read an input symbol, but it has to read the top of the stack in every transition.
Pascaline	The first mechanical calculator using gears for calculation developed in 1642.
Statement 1 is false, Statement 2 is true	According to the 5-tuple representation i.e. FA= {Q, ∑, δ, q, F} Statement 1: q ϵ Q'; Statement 2: FϵQ
stack	The transition a Push down automaton makes it additionally dependent upon the _____.
parse tree	A __________ of a derivation is a tree in which each internal node is labeled with a nonterminal.
s	The stack content
7	The number of elements in the set for the Language L={xϵ(∑r) *|length if x is at most 2} and ∑={0,1} is
1956	Noam Chomsky gave a mathematical model in _______ which is effective for writing computer languages.
FALSE	Language may be derived from other strings using the productions in a grammar.
{ 4,6}	If A = {3, 4, 6, 8} and
Context sensitive language is a subset of context free language	Which of the following statement is false?
True	Global Positioning System (GPS) calculates latitude and longitude from satellite signals.