Terminals and Nonterminals
Terminals
A terminal is a symbol which does not appear on the left-hand side of any
production. A grammar contains a set of terminal symbols (tokens) such as
the plus sign, +, the times sign, *, and other tokens defined by the
lexical analyzer such as Identifiers
Nonterminals
Nonterminals are the non-leaf nodes in a parse tree. In the
Expression grammar, E, T, and F are nonteminals. Sometimes nonterminals
are enclosed bewteen angle brackets to distinguish them from
terminals.