# Language - Nonterminal Symbol

A non terminal symbol does not appear in the resulting formal language.

They are placeholders for patterns of terminal symbols that can be generated by the nonterminal symbols.

In a context-free grammar, Non terminal symbol appears on the left side of the production.

## 3 - 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.