15) Let M be the language over {a, b, c, d, e, f} accepting all strings so that: 1. There are precisely two e's in the string. 2. Every a is immediately followed by an even number of b's. 3. Every c is immediately followed by an odd number of f's. 4. b's and f's don't occur except as provided in rules 2 and 3. 5. All c's occur after the first e. 6. All a's occur before the second e. 7. In between the two e's there are exactly twice as many c's as a's.

15) Let M be the language over {a, b, c, d, e, f} accepting all strings so that: 1. There are precisely two e's in the string. 2. Every a is immediately followed by an even number of b's. 3. Every c is immediately followed by an odd number of f's. 4. b's and f's don't occur except as provided in rules 2 and 3. 5. All c's occur after the first e. 6. All a's occur before the second e. 7. In between the two e's there are exactly twice as many c's as a's.

C++ Programming: From Problem Analysis to Program Design

8th Edition

ISBN:9781337102087

Author:D. S. Malik

Publisher:D. S. Malik

Chapter15: Recursion

Section: Chapter Questions

Problem 6PE

See similar textbooks

Similar questions

Let Cbe the language over {a, b,c, d, e, f} accepting all strings so that: 1.There are precisely two b’s in the string. 2.Every a is immediately followed by an odd number of e’s. 3.Every d is immediately followed by an even number of f’s. 4.e’s and f’s don’t occur except as provided in rules 2 and 3. 5.All a’s occur after the first b. 6.All d’s occur before the second b. 7.In between the two b’s there are exactly twice as many a’s as d’s.HINT: Don’t be intimidated by the number of rules. The way they interact actually helps you simplify the number of cases you have to deal with while constructing this grammar. a. Construct a context-free grammar generating C.Explain how your construction accounts for each rule. b. We could eliminate one rule from Cand make it regular. Which rule would that be, and why would it work? You do not need a formal proof, but you do need an explanation.
a) Give an example of a string containing 11 that is accepted by the following automaton. b) Give an example of a string of length 8 that is rejected by the following automaton. c) Describe the language of this automaton in plain English. d) Describe the language of this automaton using Regular expression.
Let M be the language over {a, b, c, d, e, f} accepting all strings so that: 1. There are precisely two e's in the string. 2. Every a is immediately followed by an even number of f's. 3. Every c is immediately followed by an odd number of b's. 4. b's and f's don't occur except as provided in rules 2 and 3. 5. All a's occur after the first e. 6. All c's occur before the second e. 7. In between the two e's there are exactly half as many a's as c's. Construct a context-free grammar generating M. You do not need an inductive proof, but you should explain how your construction accounts for each rule. We could eliminate one rule from m to make it regular. Which one? Why?
i) Draw an FA accepting the language of all strings containing no more than one occurrence of the string aa. (The string aaa contains two occurrences of aa.) over{a,b}
1. For each of the following regular expressions find a language (i.e., a set of strings over A = {a,b.c} that can be represented/described by that expression. a. a'bc + bc* b. b'aaac а. b.
. Design DFA for the following over { a,b} (ii) All strings that has atleast two occurrences of b between any two occurrence of a.
Explain with an example the situation where using read() is appropriate andalso an example where readlines() is appropriate.
1. Write regular expression for the following languages, alphabet {0,1} a. The set of strings that do not end with 11 b. The set of strings that do not contain substring 01 c. The set of strings having 0 at every 3rd position. d. Describe the language given by the regular expression 0*10*10*1(1|0)* e. Set of all strings that are at least of length 4 and contains an even number of 1’s.
5. i) Find the language L(G) overs, {a,b,c} generated by the grammer G with production: S-aSb, aS-Aa, Aab→c. ii) Write a grammer that generates the string over {a,b} not ending with ab.
The Martian language can be written in the familiar Roman alphabet, which has 21 consonants (B, C, D, F, G, H, J, K, L, M, N, P, Q, R, S, T, V, W, X, Y, Z) and 5 vowels (A, E, I, O, U). All Martian nouns begin with a consonant, followed by one or more vowel-consonant pairs. However, no consonant can appear more than once in a single noun, and no vowel can appear more than once in a single noun. For example, VUX, DIYOK, and ZOBALUT are possible Martian nouns, but X, VUV, DIYIK, and ZEZELAL are not. Recent expeditions to Mars have cast doubt on whether the Martian language can be written with exactly 21 consonants and 5 vowels. Suppose that Martian requires c consonants and v vowels, where c > 0, v > 0, and c > v. Express the number of possible Martian nouns in terms of c and v. Your answer need not be in closed form.
1.a. Write a Regular Expression Language over ∑ = {a,b,c} a set of strings terminated by a or b. .b. Write a regular expression for the set of binary strings where each string has at least one pair of consecutive zeros. c. write the regular expression for the following, where sigma = (a,b): i. string of length at least 2 ii. string of length at most 2 iii. all string starting with a and ending with b iv. Even length Strings
The Martian language can be written in the familiar Roman alphabet, which has 21 consonants (B, C, D, F, G, H, J, K, L, M, N, P, Q, R, S, T, V, W, X, Y, Z) and 5 vowels (A, E, I, O, U). All Martian nouns begin with a consonant, followed by one or more vowel-consonant pairs. However, no consonant can appear more than once in a single noun, and no vowel can appear more than once in a single noun. For example, VUX, DIYOK, and ZOBALUT are possible Martian nouns, but X, VUV, DIYIK, and ZEZELAL are not. How many Martian nouns are possible? Your answer must be a number. Briefly explain your answer.