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):||22 July 2018|
|PDF File Size:||14.5 Mb|
|ePub File Size:||14.12 Mb|
|Price:||Free* [*Free Regsitration Required]|
Theory of Computation – TOC – Computer Science- Anna University – Question bank – CS
A grammar is said to be ambiguous if it has more than one derivation trees for a sentence or in other words if it has more than one leftmost derivation or more than one rightmost derivation. Transition Diagram associated with DFA is a directed graph whose vertices corresponds to states of DFA, The edges are the transitions from one state to another.
In 2-way infinite tape TM, the tape is infinite in both directions.
Let L be a CFL. The languages that is accepted by TM is said to be recursively enumerable r. The grammar has the production P as:. A multi-tape Turing machine consists of a finite control with k-tape heads and ktapes ; each tape is infinite in both directions.
The device has a finite controlbut the tape consists of a k-dimensional array of cells infinite in all 2k directions, for some fixed k. Consider the ambiguity problem for CFGs. The set may be empty,finite or infinite. If L is an infinite language in ,then there is a finite subset of L in. Enumerable means that the strings in the language can be enumerated by the TM. The set of finite languages in is enumaerable. 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.
Universal TMs are TMs that can be programmed to solve any problem, that can be solved by any Turing machine. A lexical analyzer scans the symbols of a program to locate strings corresponding to identifiers, constants etc, and it has to remember limited amount of information.
It can enter an infinite loop so that it never halts. The components of FA model are Input tape, Read control and finite control.
If f i1,i2,………ik is defined for all i1,…. Text editors and lexical analyzers are designed as finite state systems.
We can describe TM using:. Any computation that can be done by 2-way infinite tape can also be done by standard TM. The height of the parse tree is the length of the longest path from the root to some leaf. What are the different types of language acceptances by a PDA and define them.
The class of regular sets are closed under complementation, substitution, homomorphism and inverse homomorphism. How can a TM acts as a generating device? A specific Universal Turing machine U is:. The notion of computable function can be identified with the class of partial recursive functions is known as Church-hypothesis or Church-Turing thesis.
There are no transitions from any of the halt states of any given TM. Is it true that the language accepted by a non-deterministic Turing machine is different from recursively enumerable language? TM can be used as:.
The compuyation of the Finite control represents the state and the second element represent a symbol scanned. What is a universal language Lu? Nothe language accepted by non-deterministic Turing machine is same as recursively enumerable language. Describes block structure in programming languages. NFA or Non Deterministic Finite Automaton is the one in which there exists many paths sc2303 a specific input from current state to next state. They are similar to r. This is an intermediate form in doing a derivation.
F is the set of final states.