Definition:String

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Definition

Let $\mathcal A$ be an alphabet of symbols.

A string (in $\mathcal A$) is a sequence of symbols from $\mathcal A$.


There is no limit to the number of times a particular symbol may appear in a given string.


Finite String

A string $S$ in $\mathcal A$ is a finite string if and only if the sequence of symbols of which it is composed is finite.


Infinite String

A string $S$ in $\mathcal A$ is an infinite string if and only if the sequence of symbols of which it is composed is infinite.


Also defined as

Some sources use the word string to mean a finite string, that is, what is defined on $\mathsf{Pr} \infty \mathsf{fWiki}$ as a word.


Also see


Sources