compsci-formal-language.html
* created: 2026-03-24T18:04
* modified: 2026-03-25T00:16
title
Formal language
description
A set of words over an alphabet
related notes
Formal language
This is a set of words over an alphabet, i.e. L \subseteq \sum^*.
Alphabet
A finite, non-empty set of characters which is commonly denoted as: \sum.
Examples of such Alphabets are:
- \sum := \{0,1\}
- \sum := \{a,b,c\}
Word
A finite sequence of characters from an Alphabet.
e describes the sequence without characters. See neutral element.
Examples of such Words are:
- 0: Word over \{0,1\}
- hello \ world: Word over \{ \ ,a,b,c,\dots,z \}