A.2 Notation Conventions

The notation used to describe the PIF syntax is very similar to the Backus Naur Form (BNF).

We use

teletype
for required text (terminals) - ``write it as it is''.
italics
for syntax construct names (nonterminals) - ``look at the definition''.
a | b | c
for choices - ``choose one of a, b, or c''.
a
for options - ``take or leave a''.
()
for syntactical grouping.
a
for an optional sequence - ``give zero or more instances of a''.
{a}
for a sequence - ``give one or more instances of a''.