1. {application program}.

	2. {function application}.

<operating system, programming> The process of carrying out
	the {instructions} in a computer program by a computer.

	See also {dry run}.

	(1996-05-13)

1. <tool> A program used primarily to create, manipulate,
	modify, or analyse other programs, such as a compiler or an
	editor or a cross-referencing program.  Opposite: {app},
	{operating system}.

	2. A {Unix} {application program} with a simple, "transparent"
	(typically text-stream) interface designed specifically to be
	used in programmed combination with other tools (see {filter},
	{plumbing}).

	3. <jargon> ({MIT}: general to students there) To work; to
	study (connotes tedium).  The {TMRC} Dictionary defined this
	as "to set one's brain to the grindstone".  See {hack}.

	4. <jargon, person> ({MIT}) A student who studies too much and
	hacks too little.  MIT's student humour magazine rejoices in
	the name "Tool and Die".

	[{Jargon File}]

	(1996-12-12)

1. <mathematics> A collection of {nodes} and {edges}.

	See also {connected graph}, {degree}, {directed graph}, {Moore
	bound}, {regular graph}, {tree}.

	2. <graphics> A visual representation of algebraic equations
	or data.

	(1996-09-22)

1. <mathematics> (Or "map", "mapping") If D and C are sets
	(the domain and codomain) then a function f from D to C,
	normally written "f : D -> C" is a subset of D x C such that:

	1. For each d in D there exists some c in C such that (d,c) is
	an element of f.  I.e. the function is defined for every
	element of D.

	2. For each d in D, c1 and c2 in C, if both (d,c1) and (d,c2)
	are elements of f then c1 = c2.  I.e. the function is uniquely
	defined for every element of D.

	See also {image}, {inverse}, {partial function}.

	2. <programming> Computing usage derives from the mathematical
	term but is much less strict.  In programming (except in
	{functional programming}), a function may return different
	values each time it is called with the same argument values
	and may have {side effects}.

	A {procedure} is a function which returns no value but has
	only {side-effects}.  The {C} language, for example, has no
	procedures, only functions.  {ANSI C} even defines a {type},
	{void}, for the result of a function that has no result.

	(1996-09-01)

1. <data, graphics> Data representing a two-dimensional scene.
	A digital image is composed of {pixels} arranged in a
	rectangular array with a certain height and width.  Each pixel
	may consist of one or more {bits} of information, representing
	the brightness of the image at that point and possibly
	including colour information encoded as {RGB} triples.

	{Images} are usually taken from the real world via a {digital
	camera}, {frame grabber}, or {scanner}; or they may be
	generated by computer, e.g. by {ray tracing} software.

	See also {image formats}, {image processing}.

	(1994-10-21)

	2. <mathematics> The image (or range) of a {function} is the
	set of values obtained by applying the function to all
	elements of its {domain}.  So, if f : D -> C then the set f(D)
	= \{ f(d) | d in D \} is the image of D under f.  The image is
	a subset of C, the {codomain}.

	(2000-01-19)

1. <file system> {hard link} or {symbolic link}.

	2. <hypertext> {hyperlink}.

	(1997-10-22)

<file format, filename extension> (jar) A compressed {archive}
	file containing {Java} {class} files, filename extension:
	".jar".  The {Java Development Kit} contains a tool called
	"jar" for creating .jar files, similar to the standard {Unix}
	{tar} command.  As well as archiving and compressing the Java
	class files, it also inserts a "manifest" file which can
	contain information about the class files, such as a {digital
	signature}.  Combining class files into a single archive file
	makes it possible to download them in a single {HTTP}
	transaction.  This, and the {compression}, speeds up execution
	of Java programs delivered via the {Internet}.

	(2001}-02-03)

<operating system> A {binary} file containing a program in
	{machine language} which is ready to be {execute}d (run).

	The term might also be, but generally isn't, applied to
	{scripts} which are interpreted by a {command line
	interpreter}.  Executables are distinguished in {Unix} by
	having the execute permission bits set, at least for the
	owner.  {MS-DOS} uses the {filename extension} ".exe".

	(1997-06-21)

<file system> An element of data storage in a {file system}.

	The history of computing is rich in varied kinds of files and
	{file systems}, whether ornate (e.g., {Macintosh file system}
	for a well-known case) or deficient (e.g., many simple
	pre-1980s file systems don't allow {directories}).

	However, the prototypical file has these characteristics:

	* It is a single sequence of bytes (but consider {Macintosh}
	{resource forks}).

	* It has a finite length, unlike, e.g. a {Unix} {device}.

	* It is stored in a {non-volatile storage} medium (but see
	{ramdrive}).

	* It exists (nominally) in a {directory}.

	* It has a name that it can be referred to by in file
	operations, possibly in combination with its {path}.

	Additionally, a file system may associate other information
	with a file, such as {permission} bits or other {file
	attributes}; timestamps for file creation, last revision, and
	last access; revision numbers (a` la VMS), and other kinds of
	{magic}.

	Compare: {document}.

	(1997-04-08)

1. The {supervisor} program or {operating system} on a
	computer.

	2. The entire computer system, including input/output devices,
	the {supervisor} program or {operating system} and possibly
	other {software}.

	3. Any large program.

	4. Any method or {algorithm}.

	[{Jargon File}]

[{Usenet}] 1. To duplicate a portion (or whole) of another's
	message (typically with attribution to the source) in a reply
	or followup, for clarifying the context of one's response.
	See the discussion of inclusion styles under "Hacker Writing
	Style".

	2. [{C}] "#include <disclaimer.h>" has appeared in {sig
	blocks} to refer to a notional "standard {disclaimer} file".

	[{Jargon File}]

In {object-oriented programming} sending a message to an
	{object} (to invoke a {method}) is equivalent to calling a
	{procedure} in traditional programming languages, except that
	the actual code executed may only be selected at run time
	depending on the {class} of the object.  Thus, in response to
	the message "drawSelf", the method code invoked would be
	different if the target object were a circle or a square.

	(1995-02-16)

<computer> A machine that can be programmed to manipulate
	symbols.  Computers can perform complex and repetitive
	procedures quickly, precisely and reliably and can quickly
	store and retrieve large amounts of data.

	The physical components from which a computer is constructed
	(electronic circuits and input/output devices) are known as
	"{hardware}".  Most computers have four types of hardware
	component: CPU, input, output and memory.  The CPU ({central
	processing unit}) executes programs ("{software}") which tell
	the computer what to do.  Input and output (I/O) devices allow
	the computer to communicate with the user and the outside
	world.  There are several kinds of memory - fast, expensive,
	short term memory (e.g. {RAM}) to hold intermediate results,
	and slower, cheaper, long-term memory (e.g. {magnetic disk} and
	{magnetic tape}) to hold programs and data between jobs.

	See also {analogue computer}.

	(1995-03-10)

<file system> A node in a hierarchical {file system} which
	contains zero or more other nodes - generally, {files} or
	other directories.

	Compare {folder}.

	(1997-04-10)

<networking> To be a {server}, to provide a {service}.

	E.g., "The {shttpd} serves requested documents to clients over
	a secure link."

	(1997-09-11)

<theory, programming> (Or "data type") A set of values from
	which a {variable}, {constant}, {function}, or other
	{expression} may take its value.  A type is a classification
	of data that tells the {compiler} or {interpreter} how the
	programmer intends to use it.  For example, the process and
	result of adding two variables differs greatly according to
	whether they are integers, floating point numbers, or strings.

	Types supported by most programming languages include
	{integers} (usually limited to some range so they will fit in
	one {word} of storage), {Booleans}, {floating point numbers},
	and characters.  {Strings} are also common, and are
	represented as {lists} of characters in some languages.

	If s and t are types, then so is s -> t, the type of
	{functions} from s to t; that is, give them a term of type s,
	functions of type s -> t will return a term of type t.

	Some types are {primitive} - built-in to the language, with no
	visible internal structure - e.g. Boolean; others are
	composite - constructed from one or more other types (of
	either kind) - e.g. {lists}, {arrays}, {structures}, {unions}.
	{Object-oriented programming} extends this with {classes}
	which encapsulate both the structure of a type and the
	operations that can be performed on it.

	Some languages provide {strong typing}, others allow {implicit
	type conversion} and/or {explicit type conversion}.

	(2003-12-22)

<operating system> A character string which tells a program to
	perform a specific action.  Most commands take {arguments}
	which either modify the action performed or supply it with
	input.  Commands may be typed by the user or read from a file
	by a {command interpreter}.  It is also common to refer to
	menu items as commands.

	(1997-06-21)

<operating system> A {directory} in the sense of a collection
	of computer {files}.  The term is more common in systems such
	as the {Macintosh} or {Windows 95} which have a {graphical
	user interface} and provide a graphical {file browser} in
	which directories are traditionally depicted as folders (like
	small briefcases).

	(1997-03-20)

<hypertext> A program which allows a person to read
	{hypertext}.  The browser gives some means of viewing the
	contents of {nodes} (or "pages") and of {navigating} from one
	node to another.

	{Netscape Navigator}, {NCSA} {Mosaic}, {Lynx}, and {W3} are
	examples for browsers for the {World-Wide Web}.  They act as
	{clients} to remote {web servers}.

	(1996-05-31)

1. To prepare to read or write a file.  This usually involves
	checking whether the file already exists and that the user has
	the necessary authorisation to read or write it.  The result
	of a successful open is usually some kind of {capability}
	(e.g. a {Unix} {file descriptor}) - a token that the user
	passes back to the system in order to access the file without
	further checks and finally to close the file.

	2. Abbreviation for "open (or left) parenthesis" - used when
	necessary to eliminate oral ambiguity.  To read aloud the LISP
	form (DEFUN FOO (X) (PLUS X 1)) one might say: "Open defun
	foo, open eks close, open, plus eks one, close close."

	3. Non-proprietary.  An open {standard} is one which can be
	used without payment.

	[{Jargon File}]

	(1995-01-31)

<hardware> To press and release a {button} on a {mouse} or
	other {pointing device}.  This generates an {event}, also
	specifying the screen position, which is processed by the
	{window manager} or {application program}.  On a mouse with
	more than one button, the unqualified term usually implies
	pressing the left-most button (with the right index finger),
	other buttons would be qualified, e.g. "{right-click}".
	{Keyboard} modifiers may also be used, e.g. "shift-click",
	meaning to hold down the shift key on the keyboard while
	clicking the mouse button.

	If the mouse moves while the button is pressed then this is a
	{drag}.

	(1995-03-14)

<jargon> To transfer data from one computer to another.
	Downloading usually refers to transfer from a larger "host"
	system (especially a {server} or {mainframe}) to a smaller
	"client" system, especially a {microcomputer} or specialised
	peripheral, and "{upload}" usually means from small to large.

	Others hold that, technically, download means "receive" and
	upload means "send", irrespective of the size of the systems
	involved.

	Note that in communications between ground and space,
	space-to-earth transmission is always "down" and the reverse
	"up", regardless of size.  So far the in-space machines have
	invariably been smaller; thus the upload/download distinction
	has been reversed from its usual sense.

	[{Jargon File}]

	(2003-11-04)

<memory management> /kash/ A small fast memory holding
	recently accessed data, designed to speed up subsequent access
	to the same data.  Most often applied to processor-memory
	access but also used for a local copy of data accessible over
	a network etc.

	When data is read from, or written to, {main memory} a copy is
	also saved in the cache, along with the associated main memory
	address.  The cache monitors addresses of subsequent reads to
	see if the required data is already in the cache.  If it is (a
	{cache hit}) then it is returned immediately and the main
	memory read is aborted (or not started).  If the data is not
	cached (a {cache miss}) then it is fetched from main memory
	and also saved in the cache.

	The cache is built from faster memory chips than main memory
	so a cache hit takes much less time to complete than a normal
	memory access.  The cache may be located on the same
	{integrated circuit} as the {CPU}, in order to further reduce
	the access time.  In this case it is often known as {primary
	cache} since there may be a larger, slower {secondary cache}
	outside the CPU chip.

	The most important characteristic of a cache is its {hit rate}
	- the fraction of all memory accesses which are satisfied from
	the cache.  This in turn depends on the cache design but
	mostly on its size relative to the main memory.  The size is
	limited by the cost of fast memory chips.

	The hit rate also depends on the access pattern of the
	particular program being run (the sequence of addresses being
	read and written).  Caches rely on two properties of the
	access patterns of most programs: temporal locality - if
	something is accessed once, it is likely to be accessed again
	soon, and spatial locality - if one memory location is
	accessed then nearby memory locations are also likely to be
	accessed.  In order to exploit spatial locality, caches often
	operate on several words at a time, a "{cache line}" or "cache
	block".  Main memory reads and writes are whole {cache lines}.

	When the processor wants to write to main memory, the data is
	first written to the cache on the assumption that the
	processor will probably read it again soon.  Various different
	policies are used.  In a {write-through} cache, data is
	written to main memory at the same time as it is cached.  In a
	{write-back} cache it is only written to main memory when it
	is forced out of the cache.

	If all accesses were writes then, with a write-through policy,
	every write to the cache would necessitate a main memory
	write, thus slowing the system down to main memory speed.
	However, statistically, most accesses are reads and most of
	these will be satisfied from the cache.  Write-through is
	simpler than write-back because an entry that is to be
	replaced can just be overwritten in the cache as it will
	already have been copied to main memory whereas write-back
	requires the cache to initiate a main memory write of the
	flushed entry followed (for a processor read) by a main memory
	read.  However, write-back is more efficient because an entry
	may be written many times in the cache without a main memory
	access.

	When the cache is full and it is desired to cache another line
	of data then a cache entry is selected to be written back to
	main memory or "flushed".  The new line is then put in its
	place.  Which entry is chosen to be flushed is determined by a
	"{replacement algorithm}".

	Some processors have separate instruction and data caches.
	Both can be active at the same time, allowing an instruction
	fetch to overlap with a data read or write.  This separation
	also avoids the possibility of bad {cache conflict} between
	say the instructions in a loop and some data in an array which
	is accessed by that loop.

	See also {direct mapped cache}, {fully associative cache},
	{sector mapping}, {set associative cache}.

	(1997-06-25)

<operating system> A list from which the user may select an
	operation to be performed.  This is often done with a {mouse}
	or other pointing device under a {graphical user interface}
	but may also be controlled from the keyboard.

	Menus are very convenient for beginners because they show what
	commands are available and make experimentating with a new
	program easy, often reducing the need for user documentation.
	Experienced users however, often prefer keyboard commands,
	especially for frequently user operations, because they are
	faster to use.  In situations such as text entry where the
	keyboard must be used anyway, having to move your hand to the
	mouse to invoke a menu operation is slow.

	There are many different ways of presenting menus but the most
	common are the {menu bar} (with {pull-down menus}) and the
	{context-sensitive menu}.

	The term "menu" tends to be reserved for a list of actions or
	global options, whereas a "{list box}" or other graphical
	{widget} might present any kind of choice.

	See also {menuitis}.

	(1994-12-02)

1. Executable code, especially a "pure code" portion shared
	between multiple instances of a program running in a
	{multitasking} {operating system}.

	Compare {English}.

	2. Textual material in the mainstream sense; data in ordinary
	{ASCII} or {EBCDIC} representation (see {flat ASCII}).  "Those
	are text files; you can review them using the editor."

	These two contradictory senses confuse hackers too.

	[{Jargon File}]

	(1995-03-16)

See {followup}.

<abuse> Someone who's clueless.  From the {World-Wide Web}
	message "404, URL Not Found" meaning that the document you've
	tried to access can't be located.

	"Don't bother asking him...he's 404, man".

	404 is one of the standard response codes of the {telnet}
	{protocol} on which the web's {HTTP} is based.

	The first 4 indicates a client error such as a mistyped URL.
	The middle 0 refers to a general syntax error.  The last 4
	just indicates the specific error in the group of 40x, which
	also includes 400: Bad Request, 401: Unauthorized, etc.

	(2000-03-18)

<file format, multimedia> (MIME) A {standard} for multi-part,
	{multimedia} {electronic mail} messages and {World-Wide Web}
	{hypertext} documents on the {Internet}.  MIME provides the
	ability to transfer non-textual data, such as graphics,
	{audio} and fax.  It is defined in {RFC 2045}, {RFC 2046},
	{RFC 2047}, {RFC 2048}, {RFC 2049}, and {BCP0013}.  It uses
	{mimencode} to encode binary data into {base 64} using a
	subset of {ASCII}.

	{FAQ
	(http://www.cis.ohio-state.edu/hypertext/faq/usenet/mail/mime-faq/top.html)}.

	(1995-04-04)

<text> (Or "cut and paste", after the paper, scissors and glue
	method of document production) The system supported by most
	document editing applications (e.g. {text editors}) and most
	{operating systems} that allows you to select a part of the
	document and then save it in a temporary buffer (known
	variously as the "clipboard", "cut buffer", "kill ring").  A
	"copy" leaves the document unchanged whereas a "cut" deletes
	the selected part.

	A "paste" inserts the data from the clipboard at the current
	position in the document (usually replacing any currently
	selected data).  This may be done more than once, in more than
	one position and in different documents.

	More sophisticated {operating systems} support copy and paste
	of different data types between different applications,
	possibly with automatic format conversion, e.g from {rich
	text} to plain {ASCII}.

	{GNU Emacs} uses the terms "kill" instead of "cut" and "yank"
	instead of "paste" and data is stored in the "kill ring".

	[Origin?  Macintosh?  Xerox?]

	(1998-07-01)

<data, database> An area of a {database} {record}, or
	{graphical user interface} {form}, into which a particular
	item of data is entered.

	Example usage: "The telephone number field is not really a
	numerical field", "Why do we need a four-digit field for the
	year?".

	A {database} {column} is the set of all instances of a given
	field from all records in a {table}.

	(1999-04-26)

<language, text> (XML) An initiative from the {W3C} defining
	an "extremely simple" dialect of {SGML} suitable for use on
	the {World-Wide Web}.

	{(http://www.w3.org/XML/)}.

	[Relationship to the {XSL} forthcoming subset of {DSSSL}?]

	(1997-11-20)

1. <hardware> A visually distinct mark on a display indicating
	where newly typed text will be inserted.  The cursor moves as
	text is typed and, in most modern editors, can be moved around
	within a document by the user to change the insertion point.

	2. <database> In {SQL}, a named control structure used by an
	{application program} to point to a row of data.  The position
	of the {row} is within a {table} or {view}, and the cursor is
	used interactively so select rows from columns.

	(1996-12-27)

<data, data processing, jargon> /day't*/ (Or "raw data")
	Numbers, {characters}, {images}, or other method of recording,
	in a form which can be assessed by a human or (especially)
	input into a {computer}, stored and {processed} there, or
	transmitted on some {digital channel}.  Computers nearly
	always represent data in {binary}.

	Data on its own has no meaning, only when interpreted by some
	kind of {data processing system} does it take on meaning and
	become {information}.

	People or computers can find patterns in data to perceive
	information, and information can be used to enhance
	{knowledge}.  Since knowledge is prerequisite to wisdom, we
	always want more data and information.  But, as modern
	societies verge on {information overload}, we especially need
	better ways to find patterns.

	1234567.89 is data.

	"Your bank balance has jumped 8087% to $1234567.89" is
	information.

	"Nobody owes me that much money" is knowledge.

	"I'd better talk to the bank before I spend it, because of
	what has happened to other people" is wisdom.

	(1999-04-30)

1. <programming> The prototype for an {object} in an
	{object-oriented language}; analogous to a {derived type} in a
	{procedural language}.  A class may also be considered to be a
	set of objects which share a common structure and behaviour.
	The structure of a class is determined by the {class
	variables} which represent the {state} of an object of that
	class and the behaviour is given by a set of {methods}
	associated with the class.

	Classes are related in a {class hierarchy}.  One class may be
	a specialisation (a "{subclass}") of another (one of its
	"{superclasses}") or it may be composed of other classes or it
	may use other classes in a {client-server} relationship.  A
	class may be an {abstract class} or a {concrete class}.

	See also {signature}.

	2. <programming> See {type class}.

	3. <networking> One of three types of {Internet addresses}
	distinguished by their most significant bits.

	3. <language> A language developed by the {Andrew Project}.
	It was one of the first attempts to add {object-oriented}
	features to {C}.

	(1995-05-01)

<programming> (Or "computer program", "program", "code") The
	instructions executed by a computer, as opposed to the
	physical device on which they run (the "{hardware}").

	The term was coined by the eminent statistician, {John Tukey}.

	Programs stored on {non-volatile storage} built from
	{integrated circuits} (e.g. {ROM} or {PROM}) are usually
	called {firmware}.

	Software can be split into two main types - {system software}
	and application software or {application programs}.  System
	software is any software required to support the production or
	execution of application programs but which is not specific to
	any particular application.  Examples of system software would
	include the {operating system}, {compilers}, editors and
	sorting programs.

	Examples of application programs would include an accounts
	package or a {CAD} program.  Other broad classes of
	application software include {real-time} software, {business
	software}, scientific and engineering software, {embedded
	software}, personal computer software and {artificial
	intelligence} software.

	Software includes both {source code} written by humans and
	executable {machine code} produced by {assemblers} or
	{compilers}.  It does not usually include the data processed
	by programs unless this is in a format such as {multimedia}
	which depends on the use of computers for its presentation.
	This distinction becomes unclear in cases such as {spread
	sheets} which can contain both instructions (formulae and
	{macros}) and data.  There are also various intermediate
	compiled or {semi-compiled}, forms of software such as
	{library} files and {byte-code}.

	Some claim that {documentation} (both paper and electronic) is
	also software.  Others go further and define software to be
	programs plus documentation though this does not correspond
	with common usage.

	The noun "program" describes a single, complete and
	more-or-less self-contained list of instructions, often stored
	in a single {file}, whereas "code" and "software" are
	uncountable nouns describing some number of instructions which
	may constitute one or more programs or part thereof.  Most
	programs, however, rely heavily on various kinds of {operating
	system} software for their execution.  The nounds "code" and
	"software" both refer to the same thing but "code" tends to
	suggest an interest in the implementation details whereas
	"software" is more of a user's term.

	(2002-07-21)

1. <chat> {Unix}'s simple {talk} command and {protocol}.
	write has been largely superseded by {talk} and then {irc}.

	An enhancement, {RWP}, has been proposed.

	2. <tool> A simple {text editor} for {Windows}.

	(1998-04-28)

(From the technical term "logical device", wherein a physical
	device is referred to by an arbitrary "logical" name) Having
	the role of.  If a person (say, Les Earnest at SAIL) who had
	long held a certain post left and were replaced, the
	replacement would for a while be known as the "logical" Les
	Earnest.  (This does not imply any judgment on the
	replacement).

	Compare {virtual}.

	At Stanford, "logical" compass directions denote a coordinate
	system in which "logical north" is toward San Francisco,
	"logical west" is toward the ocean, etc., even though logical
	north varies between physical (true) north near San Francisco
	and physical west near San Jose.  (The best rule of thumb here
	is that, by definition, El Camino Real always runs logical
	north-and-south.)  In giving directions, one might say: "To
	get to Rincon Tarasco restaurant, get onto {El Camino Bignum}
	going logical north."  Using the word "logical" helps to
	prevent the recipient from worrying about that the fact that
	the sun is setting almost directly in front of him.  The
	concept is reinforced by North American highways which are
	almost, but not quite, consistently labelled with logical
	rather than physical directions.

	A similar situation exists at MIT: Route 128 (famous for the
	electronics industry that has grown up along it) is a
	3-quarters circle surrounding Boston at a radius of 10 miles,
	terminating near the coastline at each end.  It would be most
	precise to describe the two directions along this highway as
	"clockwise" and "counterclockwise", but the road signs all say
	"north" and "south", respectively.  A hacker might describe
	these directions as "logical north" and "logical south", to
	indicate that they are conventional directions not
	corresponding to the usual denotation for those words.  (If
	you went logical south along the entire length of route 128,
	you would start out going northwest, curve around to the
	south, and finish headed due east, passing along one infamous
	stretch of pavement that is simultaneously route 128 south and
	Interstate 93 north, and is signed as such!)

	[{Jargon File}]

	(1995-01-24)

<jargon> Said of {software} that is functional but easily
	broken by changes in operating environment or configuration,
	or by any minor tweak to the software itself.  Also, any
	system that responds inappropriately and disastrously to
	abnormal but expected external stimuli; e.g. a {file system}
	that is usually totally scrambled by a power failure is said
	to be brittle.  This term is often used to describe the
	results of a research effort that were never intended to be
	robust, but it can be applied to commercially developed
	software, which displays the quality far more often than it
	ought to.

	Opposite of {robust}.

	[{Jargon File}]

	(1995-05-09)

1. <tool, compression, file format> To create a compressed
	{archive} (a "zip file") from one or more files using
	{PKWare}'s {PKZIP} or a compatible {archiver}.  Its use is
	spreading from {MS-DOS} now that portable implementations of
	the {algorithm} have been written.

	zip is also the name of a {Unix} archiving utility compatible
	with {PKZIP}.  {unzip} is the corresponding de-archiver.

	See also {gzip}, {tar and feather}.

	2. <storage> {Zip Drive}.

	[{Jargon File}]

	(1996-08-26)

<programming> In {logic programming}, a {predicate} applied to
	its {arguments} which the system attempts to prove by matching
	it against the {clauses} of the program.  A goal may fail or
	it may succeed in one or more ways.

	(1997-07-14)