Language - Nonterminal Symbol

About

A symbol or token is called non terminal when it does not appear in the resulting formal language.

They are derived token that are expressed via a rule with a regular expression that contains:

• either terminal token
• or other non terminal symbol.

Articles Related

Example

In a the following context free grammar

A -> a
A -> b

• The symbol A will never appears in the language.
• The language is composed of a and b but not A

A is then nonterminal symbol.

Documentation / Reference

• wiki/nonterminal