the user. The argument @var{arg} is the number of words in the
expansion.
-
The return value is the symbol that internally represents the new
abbrev, or @code{nil} if the user declines to confirm redefining an
existing abbrev.
@code{nil}, then the abbreviation ``expands'' solely by running
@var{hook}.
-
The argument @var{hook} is a function or @code{nil}. If @var{hook} is
non-@code{nil}, then it is called with no arguments after the abbrev is
replaced with @var{expansion}; point is located at the end of
abbrev symbol if it did expansion, @code{nil} otherwise.
@end deffn
-
@deffn Command abbrev-prefix-mark &optional arg
Mark current point as the beginning of an abbrev. The next call to
@code{expand-abbrev} will use the text from here to point (where it is