What is the sublanguage of L={ε, 1, 11, 111}

  • Thread starter Thread starter Nico
  • Start date Start date
  • Tags Tags
    Automata
Click For Summary
The discussion revolves around identifying the sublanguages of the language L={ε, 1, 11, 111} over the alphabet Σ={0, 1}. Participants debate two proposed sets of sublanguages, with one set excluding the empty string ε and the other including it. It is noted that ε is a valid string, leading to the conclusion that the second approach is more comprehensive. However, some participants point out omissions in both proposed answers, specifically missing combinations such as {1, 111} and {ε, 1, 11, 111}. The conversation emphasizes the need for clarity in defining sublanguages to facilitate better understanding.
Nico
Messages
2
Reaction score
0
Thread moved from the technical math forums to the schoolwork forums
TL;DR Summary: [Formal languages and automata]
Show all sublanguages of the language L={ε, 1, 11, 111} on Σ={0, 1}.

[Formal languages and automata]
Show all sublanguages of the language L={ε, 1, 11, 111} on Σ={0, 1}.

Is the answer {1}, {11}, {111}, {1, 11}, {11, 111}, {1, 11, 111}?

Or {ε}, {ε, 1}, {ε, 11}, {ε, 111}, {1, 11}, {1, 111}, {11, 111}, {ε, 1, 11}, {ε, 1, 111}, {ε, 11, 111}, {1, 11, 111}?
 
Physics news on Phys.org
If you wrote down the definition of sublanguage on ##\{0,1\}## more people could probably help.
 
Nico said:
Is the answer {1}, {11}, {111}, {1, 11}, {11, 111}, {1, 11, 111}?

Or {ε}, {ε, 1}, {ε, 11}, {ε, 111}, {1, 11}, {1, 111}, {11, 111}, {ε, 1, 11}, {ε, 1, 111}, {ε, 11, 111}, {1, 11, 111}?
In my limited understanding (from a long time ago), ε (the empty string) is just as valid as any other string.

So I’d say your first approach is incomplete and your second approach is correct.

However, I think you have some mistakes. The ones I spotted are:
You missed out {1, 111} from your first answer.
You missed out {ε,1, 11, 111} from your second answer.

There may be other omissions – I only checked quickly.
 
Thread 'Use greedy vertex coloring algorithm to prove the upper bound of χ'
Hi! I am struggling with the exercise I mentioned under "Homework statement". The exercise is about a specific "greedy vertex coloring algorithm". One definition (which matches what my book uses) can be found here: https://people.cs.uchicago.edu/~laci/HANDOUTS/greedycoloring.pdf Here is also a screenshot of the relevant parts of the linked PDF, i.e. the def. of the algorithm: Sadly I don't have much to show as far as a solution attempt goes, as I am stuck on how to proceed. I thought...

Similar threads

Replies
7
Views
1K
  • · Replies 6 ·
Replies
6
Views
1K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 7 ·
Replies
7
Views
3K
Replies
5
Views
2K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
Replies
6
Views
2K