- Read the syntax diagrams from left to right, from top to bottom,
following the path of the line.
The
>>--
symbol indicates the beginning of a statement.
The
--->
symbol indicates that the statement syntax is continued
on the next line.
The
>---
symbol indicates that a statement is continued from the previous line.
The
--><
indicates the end of a statement.
Diagrams of syntactical units other than complete statements
start with the
>---
symbol and end with the
--->
symbol.
- Keywords appear in uppercase letters (for example,
ASPACE) or upper and lower case (for example, PATHFile). They must be
spelled exactly as shown. Lower case letters are optional (for example,
you could enter the PATHFile keyword as PATHF, PATHFI, PATHFIL or
PATHFILE).
Variables appear in all lowercase letters in a special
typeface (for example, integer). They represent
user-supplied names or values.
- If punctuation marks, parentheses, or such symbols are shown, they
must be entered as part of the syntax.
- Required items appear on the horizontal line (the main path).
 >>-INSTRUCTION--required item----------------------------------><
|
- Optional items appear below the main path. If the item is optional
and is the default, the item appears above the main path.
 .-default item--.
>>-INSTRUCTION--+---------------+------------------------------><
'-optional item-'
|
- When you can choose from two or more items, they appear vertically
in a stack.
If you must choose one of the items, one item of the
stack appears on the main path.
 >>-INSTRUCTION--+-required choice1-+---------------------------><
'-required choice2-'
|
If choosing one of the items is optional, the whole stack appears
below the main path.
 >>-INSTRUCTION--+------------------+---------------------------><
+-optional choice1-+
'-optional choice2-'
|
- An arrow returning to the left above the main line indicates an item
that can be repeated. When the repeat arrow contains a separator
character, such as a comma, you must separate items with the separator
character.
 .-,---------------.
V |
>>-INSTRUCTION----repeatable item-+----------------------------><
|
A repeat arrow above a stack indicates that you can make more than one
choice from the stacked items, or repeat a single choice.