Editing a Grammar

To edit a grammar users must write a production rule on the Production editing row of the grammar box in the following way:

nonterminal symbols are denoted by uppercase letters;
terminal symbols are denoted by lowercase letters;
S denotes the scope, i. e. the starting production rule, also called the axiom;
production rules take the form showed in the next examples:

After writing a production rule, users must click on the Add button to add it to the grammar actually loaded on the grammar box.