then l2 is not regular
Proving a Language is Not Regular
Apply operations that regular languages are closed under (e g union concatenation star intersection or complement) on L and other regular languages to |
Non-regular Languages
If L is regular then L would be regular as well but it is not! Lemma If L is not regular and L = L1 ∩ L2 with L1 regular then L2 is not regular 18/19 |
How do you show that L is not regular?
To show that L is not regular, first, for all N > 0 it is necessary to choose a string w in L with w ≥ N.
For this, we choose the string aN bN .
Then, we have to show that for all ways of expressing aN bN as xyz with xy ≤ N, and y ̸= ϵ, there exists a k ≥ 0 such that x(yk)z ̸∈ L.(.
1) If L1 ∪ L2 is regular and L1 is finite, then L2 is regular.
TRUE.
Because L2 = (L1 ∪L2)−(L1 −L2).
The first part is regular by assumption, the second part is regular because it is finite (being a finite set minus something), and regular languages are closed under set difference.
CS 341 Homework 9 Languages That Are and Are Not Regular
(i) Every regular language has a regular proper subset. (j) If L1 and L2 are nonregular languages then L1 ? L2 is also not regular. |
Formal Languages Automata and Computation Identifying
There are subsets of a regular language which are not regular. 2. If L1 and L2 are nonregular then L1 ? L2 must be nonregular. 3. |
Problem Set 3 Solutions
11 août 2000 n<N. This string is not in L a contradiction. ... (1) If L1 ? L2 is regular and L1 is finite |
CS 138: Mid-quarter Examination 2
You may not leave the room during the examination even to go to the bathroom. Then L1 and L1 ? L2 are regular |
Practice Problems for Final Exam: Solutions CS 341: Foundations of
If TM M does not accept string w then ?M |
CS 121 Midterm Solutions
17 oct. 2013 (f) If L1 and L2 are finite languages then |
Non-regular Languages
Closure properties of the class of regular languages. If L L1 and L2 over ? are regular then so are. •. L. ( NB. L = {w ? ?? |
Languages That Are and Are Not Regular
Thus there are more languages than there are regular languages. L2 = decimal representations of nonnegative integers without leading 0's divisible by 2. |
1. For each of the following statements indicate whether it is true or
Let L1 is a regular language and L2 is a non?regular language and they are disjoint 900 states since no loop is possible other than the sink state. |
Homework 3 Solutions
Notice that the DFA is more complicated than the NFA. (b) Give a regular expression for L2. Also give an NFA for L2 over the alphabet ?. Answer: A regular |
CS 341 Homework 9 Languages That Are and Are Not Regular
Since Σ* is regular, L must be regular (h) If L′ = L1 ∪ L2 is a regular language and L1 is a regular language, then L2 is a regular language FALSE |
Pumping Lemma for Regular Languages - andrewcmued
Not being able to design a DFA does not constitute a proof If L1 is not regular and L2 is regular then L = L1L2 = {xy : x ∈ L1and y ∈ L2} is not regular 2 |
(if any), provide a counter exa
Let L1 is a regular language and L2 is a non−regular language and they are disjoint 900 states, since no loop is possible other than the sink state 1 |
Homework Three Solution– CSE 355 - publicasuedu
6 mar 2012 · We will show L is not regular by using the pumping lemma be regular” were true for all L1 and L2, then all languages would be regular |
Homework 4 Solutions
We then combine this with the existing s to t arc to get the new label ε ∪ (a ∪ b)( a ∪ bb Prove that the following languages are not regular (a) A1 = { www w |
Proof - CSE 105 Theory of Computation
L2 = {0n1n n > 10} A) L1 B) L2 C) Both L1 and L2 D) Neither L1 nor L2 But why is L2 not regular? •If a computation path visits the same state more than |
Chapter 4: Properties of Regular Languages∗ - UCSB Computer
Then, M = (Q,Σ, δ, q0,Q − F) accepts L1 6 Since regular languages are closed under complement and union, L1 ∪ L2 = L1 ∩ L2 is a regular language |
1 Closure Properties
Then, M = (Q,Σ, δ, q0,Q \ F) (i e , switch accept and non-accept states) accepts L Regular Languages are closed under intersection, i e , if L1 and L2 are |