Questions tagged [pumping-lemma]
213 questions
5
votes
2 answers
What is wrong with my pumping lemma proof?
Here I am going to give a proof that L = {w | w is an element of {0,1}* and w has an even number of 1's} is not regular (even though it is regular) and I would like someone to point out what is wrong with my proof.
This is a regular language…
James S
- 63
2
votes
1 answer
(Pumping Lemma for Regular Languages) Is this proof that L is not regular?
I have a language $L$:
$$L = \{w : a^ib^j; i > j \}$$
I need to prove this language is not regular using Pumping Lemma.
I need to find a suitable $w$, where $|w| \ge $ some $p$
$w = a^{p+1}b^{p}$
$w$ makes sense because it is in $L$ and has a…
Andrew Kor
- 398
1
vote
1 answer
pumping lemma $a^{n} (b a^{n-1})n$ times where $n$ decrements each time
Hi I am stuck trying to prove that the following language
$K = \{a, a^2ba, a^3ba^2ba,...\}$ is not a regular language.
Actually I simply can't find a word w that has a length of at least p and is in the language $K$.
Thanks!
SightBack
- 13
0
votes
0 answers
$L=\{0^m1^n \mid3m\leq 2n\}$ via pumping lemma
Hi I’m trying to prove that L isn’t regular
$L=\{0^m1^n \mid3m\leq2n\}.$
It’s from an exam of CS class, that’s my solution even if at some point I’m stuck.
I assume that L is regular
Let k > 0 length of the pumpling lemma
Let w = $0^{2k/3}1^k$ ∈ L…
guglielmo
- 31
0
votes
0 answers
Why doesn't $|uv|\le k$ break the pumping lemma?
Let $N = \{ab^x | x \in\mathbb{N}\}$.
Let the pumping length be $k$. So $ab^k$ belongs to $N$.
Let $u = a, v = b^k, w = \operatorname{empty}$.
Then $|uv|\le k$ does not hold. No other splitting I can find satisfies the requirements and I'm pretty…
Bob
- 3
0
votes
1 answer
How to prove that an even palindrome is not regular using pumping lemma?
As a follow up to this question
Given an alphabet $\{a, b\}$.
Why are palindromes not regular? Could you not select $x=z=(a|b)$ and $y=$ the remaining characters in the word.
For example given $aba$ could you not select $x=z=a$ and $y = b$ and…
0
votes
3 answers
Prove that the language L is not a regular language, using pumping lemma
I have a language $L$:
$$L = \{w : a^ib^j; i > j \}$$
I need to prove this language is not regular using Pumping Lemma. I'm wondering if I'm doing it correctly:
I need to find a suitable $w$, where $|w| \geq p$ (the pumping length). I choose:
$$w =…
Andrew Kor
- 398
0
votes
0 answers
Why is this choice of $y$ not permitted in using pumping lemma?
Consider this snippet shown below from, An Introduction to Formal Languages and Automata 6th Edition
by Peter Linz.
As per the text, choosing a value of $y = a^k$, where $k$ is odd is not permitted since this violates the condition of pumping…
Masroor
- 1,811
0
votes
1 answer
Pumping lemma proof and minimum length
What is the minimum pumping length for L=(0+1)1*0 ?
I'm guessing it's 2 (since it's shortest word is 00), but how do I then split into word = xyz and pump it so that it still stays in?
0
votes
1 answer
pumping lemma with prime
I am trying to show a that a $Language L$ is not regular. I have
$L = (P \{b\})^*$
Where
$P = \{ a^p | p = prime\}$
So i use the pumping lemma:
$1)\exists p\in \mathbb Z_{> 0} $
$2)S\in L$ such that $|s|\geq P$
Here I chose to string $a^pb$ since…
darrrrUC
- 331
0
votes
0 answers
Prove Prime' does not satisfy the Pumping Lemma
I have these two questions regarding the pumping lemma which, I do not quite fully understand. I was hoping someone can guide me through these questions.
$PRIME$ = {$a^i$ where $i$ is a prime number}
$PRIME′$ = {$a^i$ where $i$ is not prime}
A)…
Csci319
- 779
0
votes
1 answer
What exactly is a pumping lemma and how do you do one
So I have a pumping lemma question A{www|w ∈ {a,b}*} I have the correct answer but I'm not fully sure how it works. I'll give the answer just so people know what I'm going with
Assume A is REG let p be the pumping length x ∈ A, x=a^p b, a^p b, a^p…
Jon
- 1
- 3
-1
votes
1 answer
How to prove that a language is non-regular by using Pumping lemma with length?
I was given the following question:
Use the Pumping Lemma with length to prove that the following language is non-regular:
$L = \{b^na^{100}b^{2n}, \text{where n} = 1, 2, 3,...\}$
Use the prompts below to complete the proof
Assume
Then there…
Clint Theron
- 47