# Alphabet

[https://en.wikipedia.org/wiki/Alphabet\_(formal\_languages](https://en.wikipedia.org/wiki/Alphabet_\(formal_languages))

* formal language
* formal language theory
* string (word)
* symbol (letter)
* alphabet

In formal language theory, a **string** is a finite sequence of symbols, formed by concatenating the elements of an underlying base set; this base set is called the _alphabet of a string_.

The members of the alphabet are called **symbols**, and the written symbols of a natural language are better known as letters, although sometimes the symbols may also be referred to as characters, digits or glyphs.

The **binary alphabet**, `Σ = {0,1}`, has only two symbols as members, but still, an infinite number of **binary strings** may be formed from it.

[https://en.wikipedia.org/wiki/Alphabet\_(formal\_languages](https://en.wikipedia.org/wiki/Alphabet_\(formal_languages)) [https://en.wikipedia.org/wiki/Array\_data\_structure](https://en.wikipedia.org/wiki/Array_data_structure) [https://en.wikipedia.org/wiki/Combinatorics\_on\_words](https://en.wikipedia.org/wiki/Combinatorics_on_words) [https://en.wikipedia.org/wiki/Formal\_language](https://en.wikipedia.org/wiki/Formal_language) [https://en.wikipedia.org/wiki/Sequence](https://en.wikipedia.org/wiki/Sequence) [https://en.wikipedia.org/wiki/String\_(computer\_science](https://en.wikipedia.org/wiki/String_\(computer_science)) [https://en.wikipedia.org/wiki/String-searching\_algorithm](https://en.wikipedia.org/wiki/String-searching_algorithm) [https://en.wikipedia.org/wiki/Symbol\_(programming](https://en.wikipedia.org/wiki/Symbol_\(programming)) [https://en.wikipedia.org/wiki/Variable-width\_encoding](https://en.wikipedia.org/wiki/Variable-width_encoding)
