<nonterminal> -> <alternative> | <alternative> | <alternative> | "..."The following form denotes that optional can appear 0 or 1 times.
[<optional>]The following form denotes that can appear 0 or more times.
[<optional>]*The full Theta reference grammar is given in Appendix A. Productions from this grammar are used freely in the following chapters to give the general form for different Theta constructs in a concise manner. When the productions relevant to a given construct are presented, some nonterminals are naturally left undefined; the interested reader can find the productions for these nonterminals in the reference grammar.