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14.8.3 '@expansion{}' (==>): Indicating an Expansion
----------------------------------------------------

When an expression is a macro call, it expands into a new expression.
You can indicate the result of the expansion with the '@expansion{}'
command.

  The '@expansion{}' command is displayed as '==>', either a long arrow
with a flat base or (when that is not available) the ASCII sequence
'==>'.

  For example, the following

     @lisp
     (third '(a b c))
         @expansion{} (car (cdr (cdr '(a b c))))
         @result{} c
     @end lisp

produces

     (third '(a b c))
         ==> (car (cdr (cdr '(a b c))))
         => c

which may be read as:

     '(third '(a b c))' expands to '(car (cdr (cdr '(a b c))))'; the
     result of evaluating the expression is 'c'.

Often, as in this case, an example looks better if the '@expansion{}'
and '@result{}' commands are indented.