Can you help me understand this answer?
I'm currently studying for an exam and I came across a question regarding grammar in formal languages for which I'm pretty sure the professor got the answer wrong, I'd like to hear your idea.
The question presents this grammar:
The question asks to define the language opposite of S (complement of S) of even length, meaning describe the rule for all the words of even length that are not accepted by grammar S.
Their answer is this:
I believe this answer is wrong, as the word "aaabab" also will not be accepted by S and is not a word concatenated to itself as their answer describes.
Any thoughts? Am I missing something here?
Thanks in advance, Avi.
Never mind, after 2 freakin days i got it.
On a different note - I really wish you'd tell me if I broke some forum rules instead of just down voting, how will I know what not to do in the future?
As Jean correctly said - I should post the answer. I was wrong in my understanding of S, there don't have to be the same number of characters around the a and b, so what I said is absolutely wrong - the word "aaabab" WILL actually be accepted by S, the first "a" will be X and the rest is Y.
- How can a programming language that is specified using a context-free grammar, be capable of expressing a Turing Machine?
- How can I construct a grammar that generates this language?
- Resolve shift/reduction conflict in grammar for expressions in PLY for calls to embedded functions
- What does context mean by context-free and context-sensitive grammars?
- Constructing grammar based on given rules
- how to find the grammar of this Language?
- ANTLR4 - parse function-like structures in regular text
- Finding FIRST sets in a grammar
- Making a Grammar LL(1)
- Is the language {0^n 1^n 0^k | k != n} context free?
- CFG for A = { w | w has odd length where first, middle and last symbols are equal }, w from {0,1}* (epsilon is in the language)
- Is C++ context-free or context-sensitive?
- Relation between Left factoring a grammar and removing epsilon
- Count words in context free grammar
- What is the context free grammar for the complement of the double word over 0,1?
- How can left-factoring eliminate backtracking while there are non-terminals?
- Is this languages REGULAR / CONTEXT FREE but not REG / Nothing?
- How to enumerate the strings of a context-free grammar?
- Can epsilon production be assumed in a left recursive grammar
- Why isn't this a[1+2] accepted? - ANTLR4 Grammar error
- Regex-like syntax or CFG for generating cartesian product of concatenated string variables and literals
- What level of backtracking does this parser combinator library need?
- Shift/reduce issue in bison due to empty rule
- PEGjs: Request Help/guide in defining Arithmetic functions
- Simple arithmetic parser created with Kotlin and better-parse fails
- CFG for L={ a^n b^m : n <= m+3 , n,m>=0}
- First and follow of the non-terminals in two grammars
- Conflict in ambiguous grammar due to ordered declaration of optional blocks
- What kind of parser is a pratt parser?
- Can this language be described by a non-ambiguous BNF grammar?