The CICA Windows Explosion!/The CICA Windows Explosion! - Disc 2.iso/demo/wemdemo4.zip/INFO/LEMACS.15

GNU Info File | 1994-09-21 | 33KB | 637 lines

This is Info file ../info/lemacs, produced by Makeinfo-1.55 from the
input file lemacs.txi.
   This file documents the GNU Emacs editor.
   Copyright (C) 1985, 1986, 1988 Richard M. Stallman.  Copyright (C)
1991, 1992 Lucid, Inc.
   Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
preserved on all copies.
   Permission is granted to copy and distribute modified versions of
this manual under the conditions for verbatim copying, provided also
that the sections entitled "The GNU Manifesto", "Distribution" and "GNU
General Public License" are included exactly as in the original, and
provided that the entire resulting derived work is distributed under the
terms of a permission notice identical to this one.
   Permission is granted to copy and distribute translations of this
manual into another language, under the above conditions for modified
versions, except that the sections entitled "The GNU Manifesto",
"Distribution" and "GNU General Public License" may be included in a
translation approved by the author instead of in the original English.
File: lemacs,  Node: Glossary,  Next: Key Index,  Prev: Intro,  Up: Top
Glossary
********
Abbrev
     An abbrev is a text string which expands into a different text
     string when present in the buffer.  For example, you might define
     a short word as an abbrev for a long phrase that you want to insert
     frequently.  *Note Abbrevs::.
Aborting
     Aborting means getting out of a recursive edit (q.v.).  You can use
     the commands `C-]' and `M-x top-level' for this.  *Note Quitting::.
Auto Fill mode
     Auto Fill mode is a minor mode in which text you insert is
     automatically broken into lines of fixed width.  *Note Filling::.
Auto Saving
     Auto saving means that Emacs automatically stores the contents of
     an Emacs buffer in a specially-named file so the information will
     not be lost if the buffer is lost due to a system error or user
     error.  *Note Auto Save::.
Backup File
     A backup file records the contents that a file had before the
     current editing session.  Emacs creates backup files automatically
     to help you track down or cancel changes you later regret.  *Note
     Backup::.
Balance Parentheses
     Emacs can balance parentheses manually or automatically.  Manual
     balancing is done by the commands to move over balanced expressions
     (*note Lists::.).  Automatic balancing is done by blinking the
     parenthesis that matches one just inserted (*note Matching Parens:
     Matching.).
     To bind a key is to change its binding (q.v.).  *Note Rebinding::.
Binding
     A key gets its meaning in Emacs by having a binding which is a
     command (q.v.), a Lisp function that is run when the key is typed.
     *Note Binding: Commands.  Customization often involves rebinding a
     character to a different command function.  The bindings of all
     keys are recorded in the keymaps (q.v.).  *Note Keymaps::.
Blank Lines
     Blank lines are lines that contain only whitespace.  Emacs has
     several commands for operating on the blank lines in a buffer.
Buffer
     The buffer is the basic editing unit; one buffer corresponds to one
     piece of text being edited.  You can have several buffers, but at
     any time you are editing only one, the `selected' buffer, though
     several buffers can be visible when you are using multiple
     windows.  *Note Buffers::.
Buffer Selection History
     Emacs keeps a buffer selection history which records how recently
     each Emacs buffer was selected.  Emacs uses this list when
     choosing a buffer to select.  *Note Buffers::.
     `C' in the name of a character is an abbreviation for Control.
     *Note C-: Keystrokes.
     `C-M-' in the name of a character is an abbreviation for
     Control-Meta.  *Note C-M-: Keystrokes.
Case Conversion
     Case conversion means changing text from upper case to lower case
     or vice versa.  *Note Case::, for the commands for case conversion.
Characters
     Characters form the contents of an Emacs buffer; also, Emacs
     commands are invoked by keys (q.v.), which are sequences of one or
     more characters.  *Note Keystrokes::.
Command
     A command is a Lisp function specially defined to be able to serve
     as a key binding in Emacs.  When you type a key (q.v.), Emacs
     looks up its binding (q.v.) in the relevant keymaps (q.v.) to find
     the command to run.  *Note Commands::.
Command Name
     A command name is the name of a Lisp symbol which is a command
     (*note Commands::.).  You can invoke any command by its name using
     `M-x' (*note M-x::.).
Comments
     A comment is text in a program which is intended only for the
     people reading the program, and is marked specially so that it
     will be ignored when the program is loaded or compiled.  Emacs
     offers special commands for creating, aligning and killing
     comments.  *Note Comments::.
Compilation
     Compilation is the process of creating an executable program from
     source code.  Emacs has commands for compiling files of Emacs Lisp
     code (*note Lisp Libraries::.) and programs in C and other
     languages (*note Compilation::.).
Complete Key
     A complete key is a character or sequence of characters which,
     when typed by the user, fully specifies one action to be performed
     by Emacs.  For example, `X' and `Control-f' and `Control-x m' are
     keys.  Keys derive their meanings from being bound (q.v.) to
     commands (q.v.).  Thus, `X' is conventionally bound to a command
     to insert `X' in the buffer; `C-x m' is conventionally bound to a
     command to begin composing a mail message. *Note Keystrokes::.
Completion
     When Emacs automatically fills an abbreviation for a name into the
     entire name, that process is called completion.  Completion is
     done for minibuffer (q.v.) arguments when the set of possible
     valid inputs is known; for example, on command names, buffer
     names, and file names.  Completion occurs when you type TAB, SPC
     or RET.  *Note Completion::.
Continuation Line
     When a line of text is longer than the width of the screen, it
     takes up more than one screen line when displayed.  We say that the
     text line is continued, and all screen lines used for it after the
     first are called continuation lines.  *Note Continuation: Basic.
Control-Character
     ASCII characters with octal codes 0 through 037, and also code
     0177, do not have graphic images assigned to them.  These are the
     control characters.  Any control character can be typed by holding
     down the CTRL key and typing some other character; some have
     special keys on the keyboard.  RET, TAB, ESC, LFD and DEL are all
     control characters.  *Note Keystrokes::.
Copyleft
     A copyleft is a notice giving the public legal permission to
     redistribute a program or other work of art.  Copylefts are used
     by leftists to enrich the public just as copyrights are used by
     rightists to gain power over the public.
Current Buffer
     The current buffer in Emacs is the Emacs buffer on which most
     editing commands operate.  You can select any Emacs buffer as the
     current one.  *Note Buffers::.
Current Line
     The line point is on (*note Point::.).
Current Paragraph
     The paragraph that point is in.  If point is between paragraphs,
     the current paragraph is the one that follows point.  *Note
     Paragraphs::.
Current Defun
     The defun (q.v.) that point is in.  If point is between defuns, the
     current defun is the one that follows point.  *Note Defuns::.
Cursor
     The cursor is the rectangle on the screen which indicates the
     position called point (q.v.) at which insertion and deletion takes
     place.  The cursor is on or under the character that follows
     point.  Often people speak of `the cursor' when, strictly
     speaking, they mean `point'.  *Note Cursor: Basic.
Customization
     Customization is making minor changes in the way Emacs works.  It
     is often done by setting variables (*note Variables::.) or by
     rebinding keys (*note Keymaps::.).
Default Argument
     The default for an argument is the value that is used if you do not
     specify one.  When Emacs prompts you in the minibuffer for an
     argument, the default argument is used if you just type RET.
     *Note Minibuffer::.
Default Directory
     When you specify a file name that does not start with `/' or `~',
     it is interpreted relative to the current buffer's default
     directory.  *Note Default Directory: Minibuffer File.
Defun
     A defun is a list at the top level of parenthesis or bracket
     structure in a program.  It is so named because most such lists in
     Lisp programs are calls to the Lisp function `defun'.  *Note
     Defuns::.
     The DEL character runs the command that deletes one character of
     text.  *Note DEL: Basic.
Deletion
     Deleting text means erasing it without saving it.  Emacs deletes
     text only when it is expected not to be worth saving (all
     whitespace, or only one character).  The alternative is killing
     (q.v.).  *Note Deletion: Killing.
Deletion of Files
     Deleting a file means removing it from the file system.  *Note
     Misc File Ops::.
Deletion of Messages
     Deleting a message means flagging it to be eliminated from your
     mail file.  Until the mail file is expunged, you can undo this by
     undeleting the message.  *Note Rmail Deletion::.
Deletion of Screens
     When working under the multi-screen X-based version of Lucid GNU
     Emacs, you can delete individual screens using the Close menu item
     from the File menu.
Deletion of Windows
     When you delete a subwindow of an Emacs screen, you eliminate it
     from the screen.  Other windows expand to use up the space.  The
     deleted window can never come back, but no actual text is lost.
     *Note Windows::.
Directory
     Files in the Unix file system are grouped into file directories.
     *Note Directories: ListDir.
Dired
     Dired is the Emacs facility that displays the contents of a file
     directory and allows you to "edit the directory", performing
     operations on the files in the directory.  *Note Dired::.
Disabled Command
     A disabled command is one that you may not run without special
     confirmation.  Commands are usually disabled because they are
     confusing for beginning users.  *Note Disabling::.
Dribble File
     A file into which Emacs writes all the characters that the user
     types on the keyboard.  Dribble files are used to make a record for
     debugging Emacs bugs.  Emacs does not make a dribble file unless
     you tell it to.  *Note Bugs::.
Echo Area
     The area at the bottom of the Emacs screen which is used for
     echoing the arguments to commands, for asking questions, and for
     printing brief messages (including error messages).  *Note Echo
     Area::.
Echoing
     Echoing refers to acknowledging the receipt of commands by
     displaying them (in the echo area).  Emacs never echoes
     single-character keys; longer keys echo only if you pause while
     typing them.
Error
     An error occurs when an Emacs command cannot execute in the current
     circumstances.  When an error occurs, execution of the command
     stops (unless the command has been programmed to do otherwise) and
     Emacs reports the error by printing an error message (q.v.).
     Type-ahead is discarded.  Then Emacs is ready to read another
     editing command.
Error Messages
     Error messages are single lines of output printed by Emacs when the
     user asks for something impossible to do (such as, killing text
     forward when point is at the end of the buffer).  They appear in
     the echo area, accompanied by a beep.
     ESC is a character used as a prefix for typing Meta characters on
     keyboards lacking a META key.  Unlike the META key (which, like
     the SHIFT key, is held down while another character is typed), the
     ESC key is pressed and released, and applies to the next character
     typed.
Fill Prefix
     The fill prefix is a string that is Emacs enters at the beginning
     of each line when it performs filling.  It is not regarded as part
     of the text to be filled.  *Note Filling::.
Filling
     Filling text means moving text from line to line so that all the
     lines are approximately the same length.  *Note Filling::.
Global
     Global means `independent of the current environment; in effect
     throughout Emacs'.  It is the opposite of local (q.v.).  Examples
     of the use of `global' appear below.
Global Abbrev
     A global definition of an abbrev (q.v.) is effective in all major
     modes that do not have local (q.v.) definitions for the same
     abbrev.  *Note Abbrevs::.
Global Keymap
     The global keymap (q.v.) contains key bindings that are in effect
     unless local key bindings in a major mode's local keymap (q.v.)
     override them.*Note Keymaps::.
Global Substitution
     Global substitution means replacing each occurrence of one string
     by another string through a large amount of text.  *Note Replace::.
Global Variable
     The global value of a variable (q.v.) takes effect in all buffers
     that do not have their own local (q.v.) values for the variable.
     *Note Variables::.
Graphic Character
     Graphic characters are those assigned pictorial images rather than
     just names.  All the non-Meta (q.v.) characters except for the
     Control (q.v.) characters are graphic characters.  These include
     letters, digits, punctuation, and spaces; they do not include RET
     or ESC.  In Emacs, typing a graphic character inserts that
     character (in ordinary editing modes).  *Note Basic Editing: Basic.
Grinding
     Grinding means adjusting the indentation in a program to fit the
     nesting structure.  *Note Grinding: Indentation.
Hardcopy
     Hardcopy means printed output.  Emacs has commands for making
     printed listings of text in Emacs buffers.  *Note Hardcopy::.
     You can type HELP at any time to ask what options you have, or to
     ask what any command does.  HELP is really `Control-h'.  *Note
     Help::.
Inbox
     An inbox is a file in which mail is delivered by the operating
     system.  Rmail transfers mail from inboxes to mail files (q.v.) in
     which the mail is then stored permanently or until explicitly
     deleted.  *Note Rmail Inbox::.
Indentation
     Indentation means blank space at the beginning of a line.  Most
     programming languages have conventions for using indentation to
     illuminate the structure of the program, and Emacs has special
     features to help you set up the correct indentation.  *Note
     Indentation::.
Insertion
     Insertion means copying text into the buffer, either from the
     keyboard or from some other place in Emacs.
Justification
     Justification means adding extra spaces to lines of text to make
     them come exactly to a specified width.  *Note Justification:
     Filling.
Keyboard Macros
     Keyboard macros are a way of defining new Emacs commands from
     sequences of existing ones, with no need to write a Lisp program.
     *Note Keyboard Macros::.
     A key is a sequence of characters that, when input to Emacs,
     specify or begin to specify a single action for Emacs to perform.
     That is, the sequence is considered a single unit.  If the key is
     enough to specify one action, it is a complete key (q.v.); if it
     is less than enough, it is a prefix key (q.v.).  *Note
     Keystrokes::.
Keymap
     The keymap is the data structure that records the bindings (q.v.)
     of keys to the commands that they run.  For example, the keymap
     binds the character `C-n' to the command function `next-line'.
     *Note Keymaps::.
Kill Ring
     The kill ring is the place where all text you have killed recently
     is saved.  You can re-insert any of the killed text still in the
     ring; this is called yanking (q.v.).  *Note Yanking::.
Killing
     Killing means erasing text and saving it on the kill ring so it
     can be yanked (q.v.) later.  Some other systems call this
     "cutting".  Most Emacs commands to erase text do killing, as
     opposed to deletion (q.v.).  *Note Killing::.
Killing Jobs
     Killing a job (such as, an invocation of Emacs) means making it
     cease to exist.  Any data within it, if not saved in a file, is
     lost.  *Note Exiting::.
     A list is, approximately, a text string beginning with an open
     parenthesis and ending with the matching close parenthesis.  In C
     mode and other non-Lisp modes, groupings surrounded by other kinds
     of matched delimiters appropriate to the language, such as braces,
     are also considered lists.  Emacs has special commands for many
     operations on lists.  *Note Lists::.
Local
     Local means `in effect only in a particular context'; the relevant
     kind of context is a particular function execution, a particular
     buffer, or a particular major mode.  Local is the opposite of
     `global' (q.v.).  Specific uses of `local' in Emacs terminology
     appear below.
Local Abbrev
     A local abbrev definition is effective only if a particular major
     mode is selected.  In that major mode, it overrides any global
     definition for the same abbrev.  *Note Abbrevs::.
Local Keymap
     A local keymap is used in a particular major mode; the key bindings
     (q.v.) in the current local keymap override global bindings of the
     same keys.  *Note Keymaps::.
Local Variable
     A local value of a variable (q.v.) applies to only one buffer.
     *Note Locals::.
     `M-' in the name of a character is an abbreviation for META, one
     of the modifier keys that can accompany any character.  *Note
     Keystrokes::.
     `M-C-' in the name of a character is an abbreviation for
     Control-Meta; it means the same thing as `C-M-'.  If your terminal
     lacks a real META key, you type a Control-Meta character by typing
     ESC and then typing the corresponding Control character.  *Note
     C-M-: Keystrokes.
     `M-x' is the key which is used to call an Emacs command by name.
     You use it to call commands that are not bound to keys.  *Note
     M-x::.
     Mail means messages sent from one user to another through the
     computer system, to be read at the recipient's convenience.  Emacs
     has commands for composing and sending mail, and for reading and
     editing the mail you have received.  *Note Sending Mail::.  *Note
     Rmail::, for how to read mail.
Mail File
     A mail file is a file which is edited using Rmail and in which
     Rmail stores mail.  *Note Rmail::.
Major Mode
     The major modes are a mutually exclusive set of options each of
     which configures Emacs for editing a certain sort of text.
     Ideally, each programming language has its own major mode.  *Note
     Major Modes::.
     The mark points to a position in the text.  It specifies one end
     of the region (q.v.), point being the other end.  Many commands
     operate on the whole region, that is, all the text from point to
     the mark.  *Note Mark::.
Mark Ring
     The mark ring is used to hold several recent previous locations of
     the mark, just in case you want to move back to them.  *Note Mark
     Ring::.
Message
     See `mail'.
     Meta is the name of a modifier bit which a command character may
     have.  It is present in a character if the character is typed with
     the META key held down.  Such characters are given names that start
     with `Meta-'.  For example, `Meta-<' is typed by holding down META
     and at the same time typing `<' (which itself is done, on most
     terminals, by holding down SHIFT and typing `,').  *Note Meta:
     Keystrokes.
Meta Character
     A Meta character is one whose character code includes the Meta bit.
Minibuffer
     The minibuffer is the window that Emacs displays inside the echo
     area (q.v.) when it prompts you for arguments to commands.  *Note
     Minibuffer::.
Minor Mode
     A minor mode is an optional feature of Emacs which can be switched
     on or off independent of the features the major mode.  Each minor
     mode has a command to turn it on or off.  *Note Minor Modes::.
Mode Line
     The mode line is the line at the bottom of each text window (q.v.),
     which gives status information on the buffer displayed in that
     window.  *Note Mode Line::.
Modified Buffer
     A buffer (q.v.) is modified if its text has been changed since the
     last time the buffer was saved (or since it was created, if it has
     never been saved).  *Note Saving::.
Moving Text
     Moving text means erasing it from one place and inserting it in
     another.  This is done by killing (q.v.) and then yanking (q.v.).
     *Note Killing::.
Named Mark
     A named mark is a register (q.v.) in its role of recording a
     location in text so that you can move point to that location.
     *Note Registers::.
Narrowing
     Narrowing means creating a restriction (q.v.) that limits editing
     in the current buffer to only a part of the text in the buffer.
     Text outside that part is inaccessible to the user until the
     boundaries are widened again, but it is still there, and saving
     the file saves the invisible text.  *Note Narrowing::.
Newline
     LFD characters in the buffer terminate lines of text and are
     called newlines.  *Note Newline: Keystrokes.
Numeric Argument
     A numeric argument is a number, specified before a command, to
     change the effect of the command.  Often the numeric argument
     serves as a repeat count.  *Note Arguments::.
Option
     An option is a variable (q.v.) that allows you to customize Emacs
     by giving it a new value.  *Note Variables::.
Overwrite Mode
     Overwrite mode is a minor mode.  When it is enabled, ordinary text
     characters replace the existing text after point rather than
     pushing it to the right.  *Note Minor Modes::.
     A page is a unit of text, delimited by formfeed characters (ASCII
     Control-L, code 014) coming at the beginning of a line.  Some Emacs
     commands are provided for moving over and operating on pages.
     *Note Pages::.
Paragraphs
     Paragraphs are the medium-size unit of English text.  There are
     special Emacs commands for moving over and operating on paragraphs.
     *Note Paragraphs::.
Parsing
     We say that Emacs parses words or expressions in the text being
     edited.  Really, all it knows how to do is find the other end of a
     word or expression.  *Note Syntax::.
Point
     Point is the place in the buffer at which insertion and deletion
     occur.  Point is considered to be between two characters, not at
     one character.  The terminal's cursor (q.v.) indicates the
     location of point.  *Note Point: Basic.
Prefix Key
     A prefix key is a key (q.v.) whose sole function is to introduce a
     set of multi-character keys.  `Control-x' is an example of a prefix
     key; any two-character sequence starting with `C-x' is also a
     legitimate key.  *Note Keystrokes::.
Primary Mail File
     Your primary mail file is the file named `RMAIL' in your home
     directory, where Rmail stores all mail you receive unless you make
     arrangements to do otherwise.  *Note Rmail::.
Prompt
     A prompt is text printed to ask the user for input.  Printing a
     prompt is called prompting.  Emacs prompts always appear in the
     echo area (q.v.).  One kind of prompting happens when the
     minibuffer is used to read an argument (*note Minibuffer::.); the
     echoing which happens when you pause in the middle of typing a
     multi-character key is also a kind of prompting (*note Echo
     Area::.).
Quitting
     Quitting means cancelling a partially typed command or a running
     command, using `C-g'.  *Note Quitting::.
Quoting
     Quoting means depriving a character of its usual special
     significance.  In Emacs this is usually done with `Control-q'.
     What constitutes special significance depends on the context and
     on convention.  For example, an "ordinary" character as an Emacs
     command inserts itself; so in this context, a special character is
     any character that does not normally
     insert itself (such as DEL, for example), and quoting it makes it
     insert itself as if it were not special.  Not all contexts allow
     quoting.  *Note Quoting: Basic.
Read-only Buffer
     A read-only buffer is one whose text you are not allowed to change.
     Normally Emacs makes buffers read-only when they contain text which
     has a special significance to Emacs; for example, Dired buffers.
     Visiting a file that is write protected also makes a read-only
     buffer.  *Note Buffers::.
Recursive Editing Level
     A recursive editing level is a state in which part of the
     execution of a command involves asking the user to edit some text.
     This text may or may not be the same as the text to which the
     command was applied.  The mode line indicates recursive editing
     levels with square brackets (`[' and `]').  *Note Recursive Edit::.
Redisplay
     Redisplay is the process of correcting the image on the screen to
     correspond to changes that have been made in the text being edited.
     *Note Redisplay: Screen.
Regexp
     See `regular expression'.
Region
     The region is the text between point (q.v.) and the mark (q.v.).
     Many commands operate on the text of the region.  *Note Region:
     Mark.
Registers
     Registers are named slots in which text or buffer positions or
     rectangles can be saved for later use.  *Note Registers::.
Regular Expression
     A regular expression is a pattern that can match various text
     strings; for example, `l[0-9]+' matches `l' followed by one or more
     digits.  *Note Regexps::.
Replacement
     See `global substitution'.
Restriction
     A buffer's restriction is the amount of text, at the beginning or
     the end of the buffer, that is temporarily invisible and
     inaccessible.  Giving a buffer a nonzero amount of restriction is
     called narrowing (q.v.).  *Note Narrowing::.
     RET is the character than runs the command to insert a newline
     into the text.  It is also used to terminate most arguments read
     in the minibuffer (q.v.).  *Note Return: Keystrokes.
Saving
     Saving a buffer means copying its text into the file that was
     visited (q.v.) in that buffer.  To actually change a file you have
     edited in Emacs, you have to save it.  *Note Saving::.
Scrolling
     Scrolling means shifting the text in the Emacs window to make a
     different part ot the buffer visible.  *Note Scrolling: Display.
Searching
     Searching means moving point to the next occurrence of a specified
     string.  *Note Search::.
Selecting
     Selecting a buffer means making it the current (q.v.) buffer.
     *Note Selecting: Buffers.
Self-documentation
     Self-documentation is the feature of Emacs which can tell you what
     any command does, or give you a list of all commands related to a
     topic you specify.  You ask for self-documentation with the help
     character, `C-h'.  *Note Help::.
Sentences
     Emacs has commands for moving by or killing by sentences.  *Note
     Sentences::.
     An sexp (short for `s-expression') is the basic syntactic unit of
     Lisp in its textual form: either a list, or Lisp atom.  Many Emacs
     commands operate on sexps.  The term `sexp' is generalized to
     languages other than Lisp, to mean a syntactically recognizable
     expression.  *Note Sexps: Lists.
Simultaneous Editing
     Simultaneous editing means two users modify the same file at once.
     If simultaneous editing is not detected, you may lose your work.
     Emacs detects all cases of simultaneous editing and warns the user
     to investigate them.  *Note Simultaneous Editing: Interlocking.
String
     A string is a kind of Lisp data object which contains a sequence of
     characters.  Many Emacs variables are intended to have strings as
     values.  The Lisp syntax for a string consists of the characters in
     the string with a `"' before and another `"' after. Write a `"'
     that is part of the string as `\"' and a `\' that is part of the
     string as `\\'.  You can include all other characters, including
     newline, just by writing them inside the string. You can also
     include escape sequences as in C, such as `\n' for newline or
     `\241' using an octal character code.
String Substitution
     See `global substitution'.
Syntax Table
     The syntax table tells Emacs which characters are part of a word,
     which characters balance each other like parentheses, etc.  *Note
     Syntax::.
Tag Table
     A tag table is a file that serves as an index to the function
     definitions in one or more other files.  *Note Tags::.
Termscript File
     A termscript file contains a record of all characters Emacs sent to
     the terminal.  It is used for tracking down bugs in Emacs
     redisplay.  Emacs does not make a termscript file unless
     explicitly instructed to do so.  *Note Bugs::.
     Text has two meanings (*note Text::.):
        * Data consisting of a sequence of characters, as opposed to
          binary numbers, images, graphics commands, executable
          programs, and the like.  The contents of an Emacs buffer are
          always text in this sense.
        * Data consisting of written human language, as opposed to
          programs, or following the stylistic conventions of human
          language.
Top Level
     Top level is the normal state of Emacs, in which you are editing
     the text of the file you have visited.  You are at top level
     whenever you are not in a recursive editing level (q.v.) or the
     minibuffer (q.v.), and not in the middle of a command.  You can
     get back to top level by aborting (q.v.) and quitting (q.v.).
     *Note Quitting::.
Transposition
     Transposing two units of text means putting each one into the place
     formerly occupied by the other.  There are Emacs commands to
     transpose two adjacent characters, words, sexps (q.v.) or lines
     (*note Transpose::.).
Truncation
     Truncating text lines in the display means leaving out any text on
     a line that does not fit within the right margin of the window
     displaying it.  See also `continuation line'.  *Note Truncation:
     Basic.
Undoing
     Undoing means making your previous editing go in reverse, bringing
     back the text that existed earlier in the editing session.  *Note
     Undo::.
Variable
     A variable is Lisp object that can store an arbitrary value.
     Emacs uses some variables for internal purposes, and has others
     (known as `options' (q.v.)) you can set to control the behavior of
     Emacs.  The variables used in Emacs that you are likely to be
     interested in are listed in the Variables Index of this manual.
     *Note Variables::, for information on variables.
Visiting
     Visiting a file means loading its contents into a buffer (q.v.)
     where they can be edited.  *Note Visiting::.
Whitespace
     Whitespace is any run of consecutive formatting characters (space,
     tab, newline, and backspace).
Widening
     Widening is removing any restriction (q.v.) on the current buffer;
     it is the opposite of narrowing (q.v.).  *Note Narrowing::.
Window
     Emacs divides the screen into one or more windows, each of which
     can display the contents of one buffer (q.v.) at any time.  *Note
     Screen::, for basic information on how Emacs uses the screen.
     *Note Windows::, for commands to control the use of windows. Note
     that if you are running Emacs under X, terminology can be
     confusing: Each Emacs screen occupies a separate X window and can,
     in turn, be divided into different subwindows.
Word Abbrev
     Synonymous with `abbrev'.
Word Search
     Word search is searching for a sequence of words, considering the
     punctuation between them as insignificant.  *Note Word Search::.
Yanking
     Yanking means reinserting text previously killed.  It can be used
     to undo a mistaken kill, or for copying or moving text.  Some other
     systems call this "pasting".  *Note Yanking::.