"#def", "a b", "_$r"

An abbreviation is only recognized when you type a non-keyword character.
This can also be the <Esc> that ends Insert mode or the <CR> that ends a
command.  The non-keyword character which ends the abbreviation is inserted
after the expanded abbreviation.  An exception to this is the character <C-]>,
which is used to expand an abbreviation without inserting any extra
characters.

Example: >
   :ab hh	hello
<	    "hh<Space>" is expanded to "hello<Space>"
	    "hh<C-]>" is expanded to "hello"

The characters before the cursor must match the abbreviation.  Each type has
an additional rule:

full-id	  In front of the match is a non-keyword character, or this is where
	  the line or insertion starts.  Exception: When the abbreviation is
	  only one character, it is not recognized if there is a non-keyword
	  character in front of it, other than a space or a tab. However, for
	  the command line "'<,'>" (or any other marks) is ignored, as if the
	  command line starts after it.

end-id	  In front of the match is a keyword character, or a space or a tab,
	  or this is where the line or insertion starts.

non-id	  In front of the match is a space, tab or the start of the line or
	  the insertion.

Examples: ({CURSOR} is where you type a non-keyword character) >
   :ab foo   four old otters
<		" foo{CURSOR}"	  is expanded to " four old otters"
		" foobar{CURSOR}" is not expanded
		"barfoo{CURSOR}"  is not expanded
>
   :ab #i #include
<		"#i{CURSOR}"	  is expanded to "#include"
		">#i{CURSOR}"	  is not expanded
>
   :ab ;; <endofline>
<		"test;;"	  is not expanded
		"test ;;"	  is expanded to "test <endofline>"

To avoid the abbreviation in Insert mode: Type CTRL-V before the character
that would trigger the abbreviation.  E.g. CTRL-V <Space>.  Or type part of
the abbreviation, exit insert mode with <Esc>, re-enter insert mode with "a"
and type the rest.

To avoid the abbreviation in Command-line mode: Type CTRL-V twice somewhere in
the abbreviation to avoid it to be replaced.  A CTRL-V in front of a normal
character is mostly ignored otherwise.

It is possible to move the cursor after an abbreviation: >
   :iab if if ()<Left>

You can even do more complicated things.  For example, to consume the space
typed after an abbreviation: >
   func Eatchar(pat)
      let c = nr2char(getchar(0))
      return (c =~ a:pat) ? '' : c
   endfunc
   iabbr <silent> if if ()<Left><C-R>=Eatchar('\s')<CR>

There are no default abbreviations.

Abbreviations are never recursive.  You can use ":ab f f-o-o" without any
problem.  But abbreviations can be mapped.

				*:abbreviate-local* *:abbreviate-<buffer>*
Just like mappings, abbreviations can be local to a buffer.  This is mostly
used in a |filetype-plugin| file.  Example for a C plugin file: >
	:abb <buffer> FF  for (i = 0; i < ; ++i)
<
						*:ab* *:abbreviate*
:ab[breviate]		list all abbreviations.  The character in the first
			column indicates the mode where the abbreviation is
			used: 'i' for insert mode, 'c' for Command-line
			mode, '!' for both.  These are the same as for
			mappings, see |map-listing|.

						*:abbreviate-verbose*
When 'verbose' is non-zero, listing an abbreviation will also display where it
was last defined.  Example: >

	:verbose abbreviate
	!  teh		 the
		Last set from /home/abcd/vim/abbr.vim

See |:verbose-cmd| for more information.

:ab[breviate] {lhs}	list the abbreviations that start with {lhs}
			You may need to insert a CTRL-V (type it twice) to
			avoid that a typed {lhs} is expanded, since
			command-line abbreviations apply here.

:ab[breviate] [<expr>] [<buffer>] {lhs} {rhs}
			add abbreviation for {lhs} to {rhs}.  If {lhs} already
			existed it is replaced with the new {rhs}.  {rhs} may
			contain spaces.
			See |:map-<expr>| for the optional <expr> argument.
			See |:map-<buffer>| for the optional <buffer> argument.

						*:una* *:unabbreviate*
:una[bbreviate] [<buffer>] {lhs}
			Remove abbreviation for {lhs} from the list.  If none
			is found,