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.
|Published (Last):||23 July 2011|
|PDF File Size:||2.23 Mb|
|ePub File Size:||4.66 Mb|
|Price:||Free* [*Free Regsitration Required]|
Otherwise the problem is said to be undecidable.
A multi-tape Turing machine consists of a finite control with k-tape heads and ktapes ; each tape is infinite in both directions. Condition i is called the basis step and condition ii is called the inductive step. For example UNIX text editors uses the reg exp for substituting the strings such as: The input string is accepted by the PDA if:.
When is a trivial property? Given any TM M and an input string w, does M halt on w? The notion of computable function can be identified with the class of partial recursive functions is known as Church-hypothesis or Church-Turing witu.
Context free languages are used in:. Decidable problems have an. Finite Automata is used to model regular expression and cannot be used to represent non regular languages. Xk respectively then A X1X2….
What are the techniques for Turing machine construction? A sentential form is a string abnk a mix of variables and terminal symbols or all variables. Give an example of undecidable.
An automaton in whch the output depends on the transition and current input is called Mealy machine. What properties of recursive enumerable seta are not decidable?
CS Theory of computation RJ edition 2 and 16 marks with answers -Unit wise
Let L be a CFL. FA accepts a string x if the sequence of transitions corresponding to the symbols of x leads from the start state to accepting state. The halting problem for TMs is: The class of regular sets are closed under complementation, substitution, homomorphism and inverse homomorphism. In one move ,TM depending upon the symbol scanned by the tape head and state of the finite control:. Checking off symbols is useful method when qkestion TM recognizes a language with repeated strings and also to compare the length of substrings.
A problem whose language is recursive is said to be decidable. The lexical analyzer scans the input program and separates the tokens. So we require a PDA ,a machine that can count without limit. Simplified the definition of programming languages. Thus control unit of a computer is a finite statesystem. The leftmost square is not distinguished.
All common arithmetic functions on integers such as multiplicationn! F is the set of final states. Any computation that can be done by 2-way infinite tape can also be done by standard TM. In 2-way infinite tape TM, the tape is infinite in both directions.
There are no transitions from any of the halt states of any given TM. A TM can be used as a transducer. The set may be empty,finite or infinite. How can a TM acts as a generating device? Xk must be in Anwers.