where

- V is a finite set of (meta)symbols, or
*variables*. - T is a finite set of
*terminal symbols*. - S V is
a distinguished element of V called the
*start symbol*. - P is a finite set of
*productions*(or*rules*).

where

- X (V T), and
- Y (V T).

- X (V T) : X is a member of the set of strings composed of any mixture of variables and terminal symbols, but X is not the empty string.
- Y (V T) : Y is a member of the set of strings composed of any mixture of variables and terminal symbols; Y is allowed to be the empty string.

Copyright © 1996 by David Matuszek

Last modified Jan 29, 1996