Theory of Computation


Q81.

Which of the following statements are true? I. Every left-recursive grammar can be converted to a right-recursive grammar and vice-versa II. All \varepsilon-productions can be removed from any context-free grammar by suitable transformations III. The language generated by a context-free grammar all of whose productions are of the form x \rightarrow w or x \rightarrow wY (where, w is a string of terminals and Y is a non-terminal), is always regular IV. The derivation trees of strings generated by a context-free grammar in Chomsky Normal Form are always binary trees
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Q82.

Consider the following language: L= \{ w \in \{0,1\}^* \mid w \text{ ends with the substring } 011 \} Which one of the following deterministic finite automata accepts L?
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Q83.

Minimum number of states required in DFA accepting binary strings not ending in "101" is
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Q84.

Consider the following deterministic finite automaton (DFA)The number of strings of length 8 accepted by the above automaton is _________
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Q85.

Given a language L, define L^{i} as follows: L^{0}=\{\varepsilon \} L^{i}=L^{i-1} \cdot L for all i \gt 0 The order of a language L is defined as the smallest k such that L^{k}=L^{k+1}. Consider the language L1 (over alphabet 0) accepted by the following automaton. The order of L1 is ______
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Q86.

The minimum possible number of states of a deterministic automaton that accepts the regular language L=\{w_{1}aw_{2}|w_{1},w_{2}\in \{a,b\}^{*},|w_{1}|=2,|w_{2}|\geq 3\} is ____
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Q87.

Let \Sigma be the set of all bijections from {1,...,5} to {1,...,5}, where id denotes the identity function, i.e. id(j)=j,\forall j. Let \circ denote composition on functions. For a string x = x_1x_2 ... x_n \in \Sigma ^n, n \geq 0, let \pi(x) = x_1\circ x_2\circ ... \circ x_n. Consider the language L = \{x \in \Sigma ^* | \pi(x) = id\}. The minimum number of states in any DFA accepting L is _________ .
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Q88.

Consider the language L over the alphabet {0, 1}, given below:L = \{w \in \{0, 1\}^* | w \text{ does not contain three or more consecutive 1's} \}. The minimum number of states in a Deterministic Finite-State Automaton (DFA) for L is _____.
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Q89.

Let \delta denote that transition function and \hat{\delta} denote the extended transition function of the \epsilon- NFA whose transition table is given below: Then \hat{\delta}(q_{2},aba) is ____
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Q90.

The FSM (Finite State Machine) machine pictured in the figure above
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