I know this isn't directly related to programming, but I was wondering if anyone know how to apply the pumping lemma to the following proof: Show that L={(a^n)(b^n)(c^m) : n!=m} is not a context free language I'm pretty confident with applying pumping lemmas, but this one is really irking me. What do you think? ...
How can I convert some regular language to its equivalent Context Free Grammar? Whether the DFA corresponding to that regular expression is required to be constructed or is there some rule for the above conversion? For example, considering the following regular expression 01+10(11)* How can I describe the grammar corresponding to...
Ohh! this regular expression thing is eating my brain up. I have been reading it from Introduction to Automata Theory, Languages and Computer by Hopcroft, Motwani and Ullman. I have solved a few exercises too but could not solve the following even after trying for almost one hr. The problem is to write a regular expression that defines...
I'm working on a javascript game and I've got an automata system controlling game time and sprite animation as well as giving a hand to the path finding system for timing and such. My problem is on slow browsers the javascript loop I'm using for counting the time is not very accurate. It tends to jump around a lot. I there a way to force...
Hi, first please (bare with me)... :-( Im having a course at University ( Theory of Computation ) at first it was easy and simple BUT then we reach the context free grammer specialy the part where we should convert a grammer to Normal forms (Greibach & Chomsky) the thing that I couldnt understand so as usual I went to google and start ...
I loved the course I took in Automata Theory and Formal Languages, so naturally I started looking around the interwebs to learn what happened since the time the books on which the course was based were written. What I discovered was that the list of stuff I wasn't familiar with seemed to be very short. For example, from the list of aut...
Hello everyone! Can you give me 2 different grammars which outputs the same set of words? Illustration: Given a grammar A and B over the alphabet {0,1}, if grammar A can produce the word 0101001, grammar B could as well. If grammar B can produce 0101111 then grammar A could as well. And if grammar A can't produce 01001 then B can neit...
I have this language: {an bm | m+n is an even number} What's the proper grammar for this? ...
I need a Finite Automata Book Full of Examples that I can learn by me self and I can use to prepare for Exams. ...
I'm thinking so, because the upper bound would be the 2^n, and given that these are both finite machines, the intersection for both the n-state NFA and the DFA with 2^n or less states will be valid. Am I wrong here? ...
Do there exists any Standard Syntax for Describing the Transition Table for an NFA or DFA ? ...
Good afternoon, Does anyone know of an "out-of-the-box" implementation of Levenshtein DFA (deterministic finite automata) in .NET (or easily translatable to it)? I have a very big dictionary with more than 160000 different words, and I want to, given an inicial word w, find all known words at Levenshtein distance at most 2 of w in an ef...
Where can I get the photo of “Introduction to automata theory, languages and computation” by Hopcroft and Ullman '79 (first edition) cover in order to be able to read all the phrases placed on the cover? Obviously the ones that gave me Google.Images (from Wikipedia, Amazon and others) do not allow this. ...