How do you know if L is a non regular language?

To Use the Pumping Lemma to prove L is not regular: Choose a long string w in L, |w| ≥ m. (The choice of the string is crucial. Must pick a string that will yield a contradiction). Show that there is NO division of w into xyz (must consider all possible divisions) such that |xy| ≤ m, |y| ≥ 1 and xyiz ∈L ∀ i ≥ 0.

Is it possible for a language L to be regular while L ∗ is not regular?

If L is not regular then so is L+Σ, yet (L+Σ)∗=Σ∗ is regular. So you can see that L* is not always not regular.

Is the intersection of two non regular languages non regular?

(a) Union of two non-regular languages cannot be regular. Ans: False. Let L1 = {ambn | m ≥ n} and L2 = {ambn | m

What is a non regular language?

Definition: A language that cannot be defined by a regular expression is a nonregular language or an irregular language.

Are non regular languages countable?

The existence of non-regular languages is guaranteed by the fact that the regular languages of any alphabet are countable, and we know that the set of all subsets of strings is not countable.

Is wwR a regular language?

Use the pumping lemma to prove A={wwR|w∈{a,b}*} is not regular. Therefore the pumping lemma holds and s = xyz for some x, y, and z with the above properties. Since xy is a prefix of s with at most p symbols, it must be the case that xy = ak for some k ≤ p.

Can a regular language be infinite?

Regular languages all have finite descriptions. But the set of strings in the language can be infinite. For example the language A* consists of all strings containing zero or more A symbols, and nothing else, and is certainly infinite.

Is the intersection of a regular and non regular language regular?

2 Answers. Suppose that the two non-regular languages are distinct and have no strings in common. The intersection of these 2 languages will be the empty set, since no string exists in both languages. The empty set is a regular language, so this can happen sometimes.

What is non regular language in automata?

Definition: A language that cannot be defined by a regular expression is a nonregular language or an irregular language. 2.

What makes a language regular?

A language is a regular language if there is a finite automaton that recognizes it. For example, this machine recognizes the language of strings that have an even number of zeroes since any string that has an even number of zeroes will go from the start state to an accepting state.

What is the difference between regular languages and non-regular languages?

Every finite set represents a regular language. Example 1 – All strings of length = 2 over {a, b}* i.e. L = {aa, ab, ba, bb} is regular. Given an expression of non-regular language, but the value of parameter is bounded by some constant, then the language is regular (means it has kind of finite comparison).