Explorer for context-free grammars

This is a tool for exploring the relationship between context-free grammars, derivation trees and languages.

To make it work, you'll need a browser that supports JavaScript.

Grammar rules

• Symbols are single characters.
• Spaces are ignored.
• Alternatives may be separated with '|' or given in multiple productions with the same left-hand-side.

Example: S → aSb|c