# What is a non regular language in automata?

## What is a 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 are the differences between regular and non regular language?

Non regular languages are those who’s members can not be expressed with RE’s. Or a regular language is a language that can be modeled by finite automata while non regular languages can not. Hope this clear’s it up.

What do you understand by non regular languages?

Classic non-regular example The proof of non-regularity of a language using the pumping lemma is a proof by contradiction. The goal is to assume that the language is regular and then derive strings which are not in the language, thereby contradicting the regularity assumption.

What is differentiate regular grammar and regular expression?

If a and b are regular expression, ab (concatenation of a and b) is also regular. If a is regular expression, a* (0 or more times a) is also regular. {a, ab, abb, abbb, abbbb,….} Regular Grammar : A grammar is regular if it has rules of form A -> a or A -> aB or A -> ɛ where ɛ is a special symbol called NULL.

### What is a regular language in automata?

A regular language is a language that can be expressed with a regular expression or a deterministic or non-deterministic finite automata or state machine. A language is a set of strings which are made up of characters from a specified alphabet, or set of symbols.

### Is non-regular language context free?

A context-free language is a language generated by a context-free grammar. Here is an example of a language that is not regular (proof here) but is context-free: { a n b n ∣ n ≥ 0 } \{a^nb^n | n \geq 0\} {anbn∣n≥0}. This is the language of all strings that have an equal number of a’s and b’s.

How do you prove that a language is not regular?

Method to prove that a language L is not regular

1. Select w such that |w| ≥ c.
2. Select y such that |y| ≥ 1.
3. Select x such that |xy| ≤ c.
4. Assign the remaining string to z.
5. Select k such that the resulting string is not in L.

How can you prove that a language is non regular?

#### What is regular expression in automata with examples?

Some RE Examples

Regular Expressions Regular Set
(0 + ε)(1 + ε) L = {ε, 0, 1, 01}
(a+b)* Set of strings of a’s and b’s of any length including the null string. So L = { ε, a, b, aa , ab , bb , ba, aaa…….}
(a+b)*abb Set of strings of a’s and b’s ending with the string abb. So L = {abb, aabb, babb, aaabb, ababb, …………..}

#### What is regular language give example?

For example, let = {a, b}. Then since {a} and {b} are regular languages, {a, b} ( = {a} {b} ) and {ab} ( = {a}{b} ) are regular languages. Also since {a} is regular, {a}* is a regular language which is the set of strings consisting of a’s such as , a, aa, aaa, aaaa etc.

What is regular language explain with example?

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.