Linked Questions

1
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2answers
55 views

Is my grammar correct and context free?

I have this language $L = \{a^{n}b^{3n}c^{2m} : m,n \ge 1\}$. I have to determine a free context grammar that generates L. Looks easy BUT i have a question about the grammar I found. First things ...
0
votes
1answer
46 views

Language to regex

Let A={a,b}. So the question is to write regular expression such that L(r) which consists of all words. My answer is this: L(r)= (a+b)* a* b* (a+b)* Is this ...
1
vote
1answer
44 views

Regular expressions

I am new to theoretical cs and am working through it slowly. I have completed a simple question and was wondering if my answer is correct or not. Thank you kindly for any feedback. The question is: ...
0
votes
0answers
47 views

Is this language equivalent to this grammar?

The book that I'm reading says it is equivalent But what about the aa string ? i produce it this way : $$ S\Rightarrow S_1B\Rightarrow aS_1bB\Rightarrow aaB\Rightarrow aa $$ But that language doesn'...
1
vote
0answers
46 views

What are resources that I can use to learn about formal langauges?

What are some good resources for practice problems on formal languages? Every textbook I've seen contains few practice problems with even fewer answers. I would like a resource that has questions with ...
-1
votes
1answer
31 views

What is the language generated by this grammar?

I'm struggling to find the language generated by the following grammar: Any help would be appreciated.
0
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1answer
25 views

A grammar for my context free language {xy | x, y ∈ {a, b} ∗ , |x| =|y| , x != y}

This question is given as an exercise to me . I took a look at the solution given by the instructor which is not the same as my solution . So I thought it would be wise to ask it here considering ...
-1
votes
1answer
22 views

How can I prove that the accepted language of a given DFA or NFA or REGEX is equivalent to a given language

I found this How do I verify that a DFA is equivalent to a NFA? but as it states it is not really a good question more of how can I check myself during an exam. Because as you might know to do this by ...

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