Regular language

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.

What is regular language with example?
Is English a regular language?
What is the difference between regular and non regular language?
Is a regular language finite?
What is a non regular language?
Is Java regular language?
Are all formal languages regular?
Is a Nb N regular?
What is regular language and non regular language in automata?
Why Every finite language is regular?
How do you know if a grammar is regular?
What is the regular expression?
Are regular languages closed under reversal?
Are ambiguous grammar context free?

What is regular language with example?

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).

Is English a regular language?

The English language is regular if you consider it as a set of single words. However, English is more than a set of words in a dictionary. English grammar is the non-regular part.

What is the difference between regular and non regular language?

What is the difference between regular and non-regular languages? - Quora. Regular languages are those languages all of who's members(forgot the proper term for this 'strings' maybe) can be expressed with just regular expression(RE). Non regular languages are those who's members can not be expressed with RE's.

Is a regular language finite?

All finite languages are regular; in particular the empty string language ε = Ø* is regular. Other typical examples include the language consisting of all strings over the alphabet a, b which contain an even number of as, or the language consisting of all strings of the form: several as followed by several bs.

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.

Is Java regular language?

For example, the set of legal Java identifiers is a regular language. The set of floating point literals (strings like 8.63 or -12.8E3) is a regular language.

Are all formal languages regular?

Note that all finite languages are regular, but not all regular languages are finite; our double-0 language contains an infinite number of words ( 007 , 008 , but also 004242 and 0012345 ), but can be tested with constant memory: To test whether a word belongs in it, check whether the first symbol is 0 , and whether ...

Is a Nb N regular?

of 'b' but because value of 'n' can reach infinity, it's not possible to count up to infinity using a Finite automata. So that's why a^n b^n | n >= 0 is not regular. Finite State Automaton has no data structure (stack) - memory as in case of push down automaton.

What is regular language and non regular language in automata?

Why Every finite language is regular?

These strings can be however of any length. There is no limit on the number of strings as well as long as it can be designated to one of the equivalence class. Thus a language can be regular if even if it is infinite. Finite language means Language of which all strings are of finite length.

How do you know if a grammar is regular?

A grammar is regular if and only if is a single nonterminal and is a single terminal or a single terminal followed by a single nonterminal, that is a production is of the form X -> a or X -> aY, where X and Y are nonterminals and a is a terminal.

What is the regular expression?

A regular expression (sometimes called a rational expression) is a sequence of characters that define a search pattern, mainly for use in pattern matching with strings, or string matching, i.e. “find and replace”-like operations. ... Regular expressions are a generalized way to match patterns with sequences of characters.

Are regular languages closed under reversal?

Since regular languages are closed under complement and union, L1 ∪ L2 = L1 ∩ L2 is a regular language. Let w = s1s2 ···sn be a word over Σ. ... 4.2: The family of regular languages is closed under reversal.

Are ambiguous grammar context free?

In computer science, an ambiguous grammar is a context-free grammar for which there exists a string that can have more than one leftmost derivation or parse tree, while an unambiguous grammar is a context-free grammar for which every valid string has a unique leftmost derivation or parse tree.