Theory of computation (TOC) (CS) (CS) (CS53) ( CS) Question Bank 1 (old) – View Question Bank 2 (old) – View / Download Question bank. Anna University Department of computer science engg Fifth Semester CS theory of computation (Regulation ) Semester: 5. Third Year CSE(Sem:V) 2 marks Questions and Answers NFA can be used in theory of computation because they are more flexible and easier to use than.

Author: Dahn Kataxe
Country: Cuba
Language: English (Spanish)
Genre: Career
Published (Last): 26 March 2013
Pages: 333
PDF File Size: 20.33 Mb
ePub File Size: 19.88 Mb
ISBN: 880-5-63145-858-7
Downloads: 78053
Price: Free* [*Free Regsitration Required]
Uploader: Dairn

A parser for grammar G is a program that takes as input a string w and produces as output either a parse tree for w ,if w is a sentence of G or an error message indicating that w is not a sentence of G.

A TM can be used as a transducer. CFL are not closed under intersectioncomplementation. Questino is an intermediate form in doing a derivation.

A specific Universal Turing machine U is:. Find CFG with no useless symbols equivalent to: A function f i1,…ik computed by a Turing machine is called a partial recursive function. There are no transitions from any of the halt states of any given TM. Finite Automata is used to model regular expression and cannot be used to represent non regular languages.

Any computation that can be done by 2-way infinite tape can also be done by standard TM.

The grammar has the production P as:. This is a context free grammar notation with minor changes in format and some shorthand.


It can enter an infinite loop so that it never halts. The pumping lemma can be used to prove a variety of languages are not context free.


F is the set of final states. Context free languages are used in:. Prints a symbol on the tape cell scanned, replacing what was written there. anwsers

The input string is accepted by the PDA if:. Let R be any set of regular languages. NFA or Non Deterministic Finite Automaton is the one in which there exists many paths for a specific input from current state to next state. The tokens thory the programming language can be expressed using regular expressions. That is a G string is in L G if:. L is recursively enumerable iff satisfies the following properties:.

We can describe TM using:. Turing machine annswers change symbols on its tapewhereas the FA cannot change symbols on tape. A switching circuit consists of a finite number of gates, quesiton of which can be in any one of the two conditions 0 or 1. For example UNIX text editors uses the reg exp for substituting the strings such as: Universal TMs are TMs that can be programmed to solve any problem, that can be solved by any Turing machine.

A language is regular if it is accepted by some finite automaton. All combinations with the pattern What is the basic difference between 2-way Cs22303 and TM? The set may be empty,finite or infinite. Find out the CFL. Let P n be a ststement about a non negative integer n.



What is the crucial assumptions for encoding a TM? What are the possibilities answerx a TM when processing an input string? These expressions are used by many text editors and utilities to search bodies of text for certain patterns etc.

Write examples with diagrams. Qjestion Share Share Share Share. A lexical analyzer scans the symbols of a program to locate strings corresponding to identifiers, constants etc, and it has to conputation limited amount of information. What properties of recursive enumerable seta are not decidable? What is canonical ordering? In 2-way infinite tape TM, the tape is infinite in both directions.

The finite control FC stores a limited amount of information. The class of regular sets are closed under complementation, substitution, homomorphism and clmputation homomorphism. Automaton is a abstact computing device. M is a DFSM that.

Describes block structure in programming languages. Computer scientists describes the programming languages by a notation called Backus- Naur Form. The notion of computable function can be identified with the class of partial recursive functions is known as Church-hypothesis or Church-Turing thesis. They are similar to r.

The language accepted by M is: