@d
: Define outer macro, and mark
This command begins the definition part.
@d
defines an outer macro (just as @D
does), and also marks the
next identifier as defined in the present section. It is equivalent to
@d
==@D@[
(see AT[).
The distinction between @d
and @D
is analagous to the
distinction between @a
and @A
. See ATa.