

@node Introduction (Introduction), Syntax, Top, Top
@chapter Introduction

@menu
* Scope::			
* Organization of the Document::  
* Referenced Publications::	
* Definitions::			
* Conformance::			
* Language Extensions::		
* Language Subsets::		
* Deprecated Language Features::  
* Symbols in the COMMON-LISP Package::	
@end menu

@node Scope, Organization of the Document, Introduction (Introduction), Introduction (Introduction)
@section Scope, Purpose, and History

@c including concept-history

@menu
* Scope and Purpose::		
* History::			
@end menu

@node Scope and Purpose, History, Scope, Scope
@subsection Scope and Purpose

The specification set forth in this document is designed to promote
the portability of @r{Common Lisp} programs among a variety of data processing
systems. It is a language specification aimed at an audience of
implementors and knowledgeable programmers. It is neither a tutorial nor
an implementation guide.

@node History,  , Scope and Purpose, Scope
@subsection History

Lisp is a family of languages with a long history.  Early key ideas in
Lisp were developed by John McCarthy during the 1956 Dartmouth Summer
Research Project on Artificial Intelligence.  McCarthy's motivation
was to develop an algebraic list processing language for artificial
intelligence work.
Implementation efforts for early dialects of Lisp were undertaken on
the IBM~704, the IBM~7090, the Digital Equipment Corporation (DEC) PDP-1,
the DEC~PDP-6, and the PDP-10. The primary dialect of Lisp between
1960 and 1965 was Lisp~1.5. By the early 1970's there were two
predominant dialects of Lisp, both arising from these early efforts:
MacLisp and Interlisp.
For further information about very early Lisp dialects, 
see {The Anatomy of Lisp} or {Lisp 1.5 Programmer's Manual}.

MacLisp improved on the Lisp~1.5 notion of special variables and error
handling. MacLisp also introduced the concept of functions that could take
a variable number of arguments, macros, arrays, non-local dynamic
exits, fast arithmetic, the first good Lisp compiler, and an emphasis
on execution speed. 
By the end of the 1970's, MacLisp was in use at over 50 sites.
For further information about Maclisp, 
see {Maclisp Reference Manual, Revision~0} or {The Revised Maclisp Manual}.

Interlisp introduced many ideas into Lisp programming environments and
methodology. One of the Interlisp ideas that influenced @r{Common Lisp} was an iteration
construct implemented by Warren Teitelman that inspired the @b{loop}
macro used both on the Lisp Machines and in MacLisp, and now in @r{Common Lisp}.
For further information about Interlisp,
see {Interlisp Reference Manual}.

Although the first implementations of Lisp were on the IBM~704 and the
IBM~7090, later work focussed on the DEC
PDP-6 and, later, PDP-10 computers, the latter being the mainstay of
Lisp and artificial intelligence work at such places as 
Massachusetts Institute of Technology (MIT), Stanford University,
and 
Carnegie Mellon University (CMU) from the mid-1960's through much of the 1970's.
The PDP-10 computer and its predecessor the PDP-6 computer were, by
design, especially well-suited to Lisp because they had 36-bit words
and 18-bit addresses. This architecture allowed a @i{cons} cell to be
stored in one word; single instructions could extract the 
@i{car} and @i{cdr}
parts.  The PDP-6 and PDP-10 had fast, powerful stack instructions
that enabled fast function calling.
But the limitations of the PDP-10 were evident by 1973: it supported a
small number of researchers using Lisp, and the small, 18-bit address
space (2^{18} = 262,144 words) limited the size of a single
program.
One response to the address space problem was the Lisp Machine, a
special-purpose computer designed to run Lisp programs.  The other
response was to use general-purpose computers with address spaces
larger than 18~bits, such as the DEC VAX and
the S-1~Mark~IIA.
For further information about S-1 Common Lisp, see ``{S-1 Common Lisp Implementation}.''

The Lisp machine concept was developed in the late 1960's.  In the
early 1970's, Peter Deutsch, working with 
Daniel Bobrow, implemented a Lisp on the
Alto, a single-user minicomputer, using microcode to interpret a
byte-code implementation language. Shortly thereafter, Richard
Greenblatt began work on a different hardware and instruction set
design at MIT.
Although the Alto was not a total success as a Lisp machine, a dialect
of Interlisp known as Interlisp-D became available on the D-series
machines manufactured by Xerox---the Dorado, Dandelion,
Dandetiger, and Dove (or Daybreak).
An upward-compatible extension of MacLisp called Lisp
Machine Lisp became available on the early MIT Lisp Machines.
Commercial Lisp machines from Xerox, Lisp Machines (LMI), and
Symbolics were on the market by 1981.
For further information about Lisp Machine Lisp, see {Lisp Machine Manual}.

During the late 1970's, Lisp Machine Lisp began to expand towards a
much fuller language.  Sophisticated lambda lists, 
@t{setf}, multiple values, and structures
like those in @r{Common Lisp} are the results of early
experimentation with programming styles by the Lisp Machine group.
Jonl White and others migrated these features to MacLisp.
Around 1980, Scott Fahlman and others at CMU began work on a Lisp to
run on the Scientific Personal Integrated Computing
Environment (SPICE) workstation.  One of the goals of the project was to
design a simpler dialect than Lisp Machine Lisp.

The Macsyma group at MIT began a project during the late 1970's called
the New Implementation of Lisp (NIL) for the VAX, which was headed by
White.  One of the stated goals of the NIL project was to fix many of
the historic, but annoying, problems with Lisp while retaining significant 
compatibility with MacLisp.  At about the same time, a research group at
Stanford University and Lawrence Livermore National Laboratory headed
by Richard P. Gabriel began the design of a Lisp to run on the
S-1~Mark~IIA supercomputer.  S-1~Lisp, never completely
functional, was the test bed for adapting advanced compiler techniques
to Lisp implementation.  Eventually the S-1 and NIL groups
collaborated.
For further information about the NIL project,
see ``{NIL---A Perspective}.''

The first effort towards Lisp standardization was made in 1969, 
when Anthony Hearn and Martin Griss at the University of Utah 
defined Standard Lisp---a subset of Lisp~1.5 and other dialects---to 
transport REDUCE, a symbolic algebra system.
During the 1970's, the Utah group implemented first a retargetable
optimizing compiler for Standard Lisp,
and then an extended implementation known as Portable Standard Lisp (PSL).
By the mid 1980's, PSL ran on about a dozen kinds of computers.
For further information about Standard Lisp, see ``{Standard LISP Report}.''

PSL and Franz Lisp---a MacLisp-like dialect for Unix machines---were 
the first examples of widely available Lisp dialects on multiple 
hardware platforms. 

One of the most important developments in Lisp occurred during the
second half of the 1970's: Scheme. Scheme, designed by Gerald J.
Sussman and Guy L. Steele Jr., is a simple dialect of Lisp whose
design brought to Lisp some of the ideas from programming language
semantics developed in the 1960's.  Sussman was one of the prime
innovators behind many other advances in Lisp technology from the late
1960's through the 1970's.
The major contributions of Scheme were lexical scoping, lexical
closures, first-class continuations, and simplified syntax (no
separation of value cells and function cells). Some of these contributions made
a large impact on the design of @r{Common Lisp}.
For further information about Scheme, see {IEEE Standard for the Scheme Programming Language} or ``{Revised^3 Report on the Algorithmic Language Scheme}.''

In the late 1970's object-oriented programming concepts started to
make a strong impact on Lisp. 
At MIT, certain ideas from Smalltalk made their way into several
widely used programming systems.
Flavors, an object-oriented programming system with multiple inheritance, 
was developed at MIT for the Lisp machine community by Howard Cannon and others.
At Xerox, the experience with Smalltalk and 
Knowledge Representation Language (KRL) led to the development of 
Lisp Object Oriented Programming System (LOOPS) and later Common LOOPS.
For further information on Smalltalk, see {Smalltalk-80: The Language and its Implementation}.
For further information on Flavors, see {Flavors: A Non-Hierarchical Approach to Object-Oriented Programming}.

These systems influenced the design of the Common Lisp Object System (CLOS).
CLOS was developed specifically for this standardization effort,
and was separately written up in ``Common Lisp Object System Specification.''  However, minor details
of its design have changed slightly since that publication, and that paper 
should not be taken as an authoritative reference to the semantics of the
object system as described in this document.

In 1980 Symbolics and LMI were developing Lisp Machine Lisp; stock-hardware
implementation groups were developing NIL, Franz Lisp, and PSL; Xerox
was developing Interlisp; and the SPICE project at CMU was developing
a MacLisp-like dialect of Lisp called SpiceLisp.

In April 1981, after a DARPA-sponsored meeting concerning the
splintered Lisp community, Symbolics, the SPICE project, the NIL
project, and the S-1~Lisp project joined together to define
@r{Common Lisp}.  Initially spearheaded by White and Gabriel, the
driving force behind this grassroots effort was provided by Fahlman,
Daniel Weinreb, David Moon, Steele,  and Gabriel.
@r{Common Lisp} was designed as a description of a family of languages.  The
primary influences on @r{Common Lisp} were Lisp Machine Lisp, MacLisp, NIL,
S-1~Lisp, Spice Lisp, and Scheme.
@i{Common Lisp: The Language} is a description of that design.  Its
semantics were intentionally underspecified in places where it was
felt that a tight specification would overly constrain @r{Common Lisp}
research and use.

In 1986 X3J13 was formed as a technical working group to
produce a draft for an ANSI @r{Common Lisp} standard. Because of the
acceptance of @r{Common Lisp}, the goals of this group differed from those of
the original designers. These new goals included stricter
standardization for portability, an object-oriented programming
system, a condition system, iteration facilities, and a way to handle
large character sets.  To accommodate those
goals, a new language specification, this
document, was developed.

@c end of including concept-history

@node Organization of the Document, Referenced Publications, Scope, Introduction (Introduction)
@section Organization of the Document

@c including concept-organization

This is a reference document, not a tutorial document.  Where possible
and convenient, the order of presentation has been chosen so that the
more primitive topics precede those that build upon them;  however,
linear readability has not been a priority.

This document is divided into chapters by topic.
Any given chapter might contain conceptual material, dictionary entries, or both.

@i{Defined names} within the dictionary portion of a chapter are
grouped in a way that brings related topics into physical proximity.
Many such groupings were possible,
and no deep significance should be inferred from the particular grouping that was chosen.
To see @i{defined names} grouped alphabetically, consult the index.
For a complete list of @i{defined names}, see @ref{Symbols in the COMMON-LISP Package}.

In order to compensate for the sometimes-unordered portions of this document, 
a glossary has been provided; see @ref{Glossary}.
The glossary provides connectivity by providing easy access to 
definitions of terms, and in some cases by providing examples or 
cross references to additional conceptual material.

For information about notational conventions used in this document,
see @ref{Definitions}.

For information about conformance, see @ref{Conformance}. 

For information about extensions and subsets, see @ref{Language Extensions}
and @ref{Language Subsets}.

For information about how @i{programs} in the language are parsed by the
@i{Lisp reader}, see @ref{Syntax}.

For information about how @i{programs} in the language are @i{compiled}
and @i{executed}, see @ref{Evaluation and Compilation}.

For information about data types, see @ref{Types and Classes}.
Not all @i{types} and @i{classes} are defined in this chapter;
many are defined in chapter corresponding to their topic--for example,
the numeric types are defined in @ref{Numbers}.
For a complete list of @i{standardized} @i{types}, 
see @i{Figure~4--2}.

For information about general purpose control and data flow,
see @ref{Data and Control Flow} or @ref{Iteration}.

@c end of including concept-organization

@node Referenced Publications, Definitions, Organization of the Document, Introduction (Introduction)
@section Referenced Publications

@c including concept-references

@table @asis

@item @t{*}  
{The Anatomy of Lisp},
        John Allen, McGraw-Hill, Inc., 1978.

@item @t{*}  
{The Art of Computer Programming, Volume 3},
             Donald E. Knuth, Addison-Wesley Company (Reading, MA), 1973.

@item @t{*}  
{The Art of the Metaobject Protocol},
	Kiczales et al., MIT Press (Cambridge, MA), 1991.

@item @t{*}  
``Common Lisp Object System Specification,''
        D. Bobrow, L. DiMichiel, R.P. Gabriel, S. Keene, G. Kiczales, D. Moon,
        @i{SIGPLAN Notices} V23, September, 1988.

@item @t{*}  
{Common Lisp: The Language},
        Guy L. Steele Jr., Digital Press (Burlington, MA), 1984.

@item @t{*}  
{Common Lisp: The Language, Second Edition},
        Guy L. Steele Jr., Digital Press (Bedford, MA), 1990.

@item @t{*}  
{Exceptional Situations in Lisp},
	Kent M. Pitman,
	@i{Proceedings of the First European Conference
	     on the Practical Application of LISP\/}
        (EUROPAL '90),
	Churchill College, Cambridge, England,
	March 27-29, 1990.

@item @t{*}  
{Flavors: A Non-Hierarchical Approach to Object-Oriented Programming},
	Howard I. Cannon, 1982.

@item @t{*}  
{IEEE Standard for Binary Floating-Point Arithmetic},
        ANSI/IEEE Std 754-1985,
        Institute of Electrical and Electronics Engineers, Inc. (New York), 1985.

@item @t{*}  
{IEEE Standard for the Scheme Programming Language},
	IEEE Std 1178-1990,
	Institute of Electrical and Electronic Engineers, Inc. (New York), 1991.

@item @t{*}  
{Interlisp Reference Manual}, Third Revision,
	Teitelman, Warren, et al,
	Xerox Palo Alto Research Center (Palo Alto, CA), 1978.

@item @t{*}  
@r{ISO 6937/2},
	@i{Information processing---Coded character sets 
           for text communication---Part 2: Latin alphabetic and non-alphabetic
           graphic characters}, 
	ISO, 1983.

@item @t{*}  
{Lisp 1.5 Programmer's Manual},
	John McCarthy, MIT Press (Cambridge, MA), August, 1962.

@item @t{*}  
{Lisp Machine Manual},
	D.L. Weinreb and D.A. Moon,
	Artificial Intelligence Laboratory, MIT (Cambridge, MA), July, 1981.

@item @t{*}  
{Maclisp Reference Manual, Revision~0},
	David A. Moon, Project MAC (Laboratory for Computer Science),
        MIT (Cambridge, MA), March, 1974.

@item @t{*}  
``{NIL---A Perspective},'' 
        JonL White, @i{Macsyma User's Conference}, 1979.

@item @t{*}  
{Performance and Evaluation of Lisp Programs},
	Richard P. Gabriel, MIT Press (Cambridge, MA), 1985.

@item @t{*}  
``{Principal Values and Branch Cuts in Complex APL},'' 
        Paul Penfield Jr., @i{APL 81 Conference Proceedings},
        ACM SIGAPL (San Francisco, September 1981), 248-256.
        Proceedings published as @i{APL Quote Quad 12}, 1 (September 1981).

@item @t{*}  
{The Revised Maclisp Manual},
	Kent M. Pitman, 
	Technical Report 295,
	Laboratory for Computer Science, MIT (Cambridge, MA), May 1983.

@item @t{*}  
``{Revised^3 Report on the Algorithmic Language Scheme},''
        Jonathan Rees and William Clinger (editors), 
        @i{SIGPLAN Notices} V21, #12, December, 1986.

@item @t{*}  
``S-1 Common Lisp Implementation,''
	R.A. Brooks, R.P. Gabriel, and G.L. Steele,
	@i{Conference Record of the 1982 ACM Symposium on Lisp and Functional Programming},
	108-113, 1982.

@item @t{*}  
@i{Smalltalk-80: The Language and its Implementation},
        A. Goldberg and D. Robson, Addison-Wesley, 1983.

@item @t{*}  
``{Standard LISP Report},''
        J.B. Marti, A.C. Hearn, M.L. Griss, and C. Griss,
        @i{SIGPLAN Notices} V14, #10, October, 1979.

@item @t{*}  
{Webster's Third New International Dictionary
 the English Language, Unabridged},
	Merriam Webster (Springfield, MA), 1986.

@item @t{*}  
@i{XP: A Common Lisp Pretty Printing System},
        R.C. Waters,
	Memo 1102a,
	Artificial Intelligence Laboratory, MIT (Cambridge, MA), September 1989.

@end table

@c end of including concept-references

@node Definitions, Conformance, Referenced Publications, Introduction (Introduction)
@section Definitions

@c including concept-definitions

This section contains notational conventions and definitions of terms
used in this manual.

@menu
* Notational Conventions::	
* Error Terminology::		
* Sections Not Formally Part Of This Standard::	 
* Interpreting Dictionary Entries::  
@end menu

@node Notational Conventions, Error Terminology, Definitions, Definitions
@subsection Notational Conventions

@ITindex{notation}

The following notational conventions are used throughout this document.

@menu
* Font Key::			
* Modified BNF Syntax::		
* Splicing in Modified BNF Syntax::  
* Indirection in Modified BNF Syntax::	
* Additional Uses for Indirect Definitions in Modified BNF Syntax::  
* Special Symbols::		
* Objects with Multiple Notations::  
* Case in Symbols::		
* Numbers (Objects with Multiple Notations)::  
* Use of the Dot Character::	
* NIL::				
* Designators::			
* Nonsense Words::		
@end menu

@node Font Key, Modified BNF Syntax, Notational Conventions, Notational Conventions
@subsubsection Font Key

@ITindex{font key}

Fonts are used in this document to convey information.

@table @asis

@item @i{name}  
Denotes a formal term whose meaning is defined in the Glossary.
When this font is used, the Glossary definition takes precedence 
over normal English usage.

Sometimes a glossary term appears subscripted, 
as in ``@i{whitespace}_2.''  
Such a notation selects one particular Glossary definition out of several,
in this case the second.
The subscript notation for Glossary terms is generally used where the
context might be insufficient to disambiguate among the available definitions.

@item @i{name}
@IGindex{name}

Denotes the introduction of a formal term locally to the current text.
There is still a corresponding glossary entry, and is formally equivalent
to a use of ``@i{name},'' but the hope is that making such uses 
conspicuous will save the reader a trip to the glossary in some cases.

@item @b{name}  
Denotes a symbol in the @t{COMMON-LISP} @i{package}.
For information about @i{case} conventions,
see @ref{Case in Symbols}.

@item @t{name}  
Denotes a sample @i{name} or piece of @i{code} that a programmer
might write in @r{Common Lisp}.

This font is also used for certain @i{standardized} names that are not
names of @i{external symbols} of the @t{COMMON-LISP} @i{package}, 
such as @i{keywords}_1,
        @i{package} @i{names},
    and @i{loop keywords}.

@item @i{name}  
Denotes the name of a @i{parameter} or @i{value}.

In some situations the notation ``<<@i{name}>>'' (@i{i.e.}, the same font,
but with surrounding ``angle brackets'') is used instead in order to
provide better visual separation from surrounding characters.  These
``angle brackets'' are metasyntactic, and never actually appear in program
input or output.

@end table

@node Modified BNF Syntax, Splicing in Modified BNF Syntax, Font Key, Notational Conventions
@subsubsection Modified BNF Syntax

@ITindex{bnf key}

This specification uses an extended Backus Normal Form (BNF) to
describe the syntax of @r{Common Lisp} @i{macro forms} and @i{special forms}.
This section discusses the syntax of BNF expressions.

@node Splicing in Modified BNF Syntax, Indirection in Modified BNF Syntax, Modified BNF Syntax, Notational Conventions
@subsubsection Splicing in Modified BNF Syntax

The primary extension used is the following:

@center [[O]]

An expression of this form appears whenever a list of elements is
to be spliced into a larger structure and the elements can appear in
any order. The symbol O represents a description of the syntax of
some number of syntactic elements to be spliced; that description must
be of the form

@center O_1 | ... | O_l

@noindent
where each O_i can be of the form S or of
the form S@r{*} or of the form S^1.

The expression [[O]] means that a list of the form

@center (O_@{i_1@}... O_@{i_j@})  1<= j

@noindent
is spliced into the enclosing expression,
such that if n != m and 1<= n,m<= j,
then either O_@{i_n@}!= O_@{i_m@}
         or O_@{i_n@} = O_@{i_m@} = Q_k, 
where for some 1<= k <= n, O_k is of the form Q_k@r{*}.

Furthermore, for each O_@{i_n@} that is of the form Q_k^1,
that element is required to appear somewhere in the list to be spliced.

For example, the expression

@t{(x [[A | B@r{*} | C]] y)}

@noindent
means that at most one @t{A}, any number of @t{B}'s, and
at most one @t{C} can occur in any order.
It is a description of any of these:

@example
 (x y)
 (x B A C y)
 (x A B B B B B C y)
 (x C B A B B B y)
@end example

@noindent
but not any of these:

@example
 (x B B A A C C y)
 (x C B C y)
@end example

@noindent
In the first case, both @t{A} and @t{C} appear too often,
and in the second case @t{C} appears too often.

The notation [[O_1 | O_2 | ...]]^+ 
adds the additional restriction that at least one item from among the possible
choices must be used.  For example:

@t{(x [[A | B@r{*} | C]]^+ y)}

@noindent
means that at most one @t{A}, any number of @t{B}'s, and
at most one @t{C} can occur in any order, but that in any case at least
one of these options must be selected.
It is a description of any of these:

@example
 (x B y)
 (x B A C y)
 (x A B B B B B C y)
 (x C B A B B B y)
@end example

@noindent
but not any of these:

@example
 (x y)
 (x B B A A C C y)
 (x C B C y)
@end example

@noindent
In the first case, no item was used;
in the second case, both @t{A} and @t{C} appear too often;
and in the third case @t{C} appears too often.

Also, the expression:

@t{(x [[A^1 | B^1 | C]] y)}

@noindent
can generate exactly these and no others:

@example
 (x A B C y)
 (x A C B y)
 (x A B y)
 (x B A C y)
 (x B C A y)
 (x B A y)
 (x C A B y)
 (x C B A y)
@end example

@node Indirection in Modified BNF Syntax, Additional Uses for Indirect Definitions in Modified BNF Syntax, Splicing in Modified BNF Syntax, Notational Conventions
@subsubsection Indirection in Modified BNF Syntax

An indirection extension is introduced in order to make this
new syntax more readable:

@center !@i{O}

@noindent
If @i{O} is a non-terminal symbol, the right-hand side
of its definition is substituted for the entire expression 
!@i{O}.  For example, the following BNF is equivalent to
the BNF in the previous example:

@t{(x [[!@i{O}]] y)}

@w{@i{O} ::=@t{A} | @t{B}@r{*} | @t{C}}

@node Additional Uses for Indirect Definitions in Modified BNF Syntax, Special Symbols, Indirection in Modified BNF Syntax, Notational Conventions
@subsubsection Additional Uses for Indirect Definitions in Modified BNF Syntax

In some cases, an auxiliary definition in the BNF might appear to be unused
within the BNF, but might still be useful elsewhere.  For example, consider the
following definitions:

@code{case}  @i{keyform  @{!@i{normal-clause}@}{*} @r{[}!@i{otherwise-clause}@r{]}} @result{}  @i{@{@i{result}@}{*}}

@code{ccase}  @i{keyplace @{!@i{normal-clause}@}{*}} @result{}  @i{@{@i{result}@}{*}}

@code{ecase}  @i{keyform  @{!@i{normal-clause}@}{*}} @result{}  @i{@{@i{result}@}{*}}

@w{@i{normal-clause} ::=@r{(}keys @{@i{form}@}{*}@r{)}}

@w{@i{otherwise-clause} ::=@r{(}@{otherwise | t@} @{@i{form}@}{*}@r{)}}

@w{@i{clause} ::=normal-clause | otherwise-clause}

Here the term ``@i{clause}'' might appear to be ``dead'' in that it
is not used in the BNF.  However, the purpose of the BNF is not just to guide parsing,
but also to define useful terms for reference in the descriptive text which follows.
As such, the term ``@i{clause}'' might appear in text that follows,
as shorthand for ``@i{normal-clause} or @i{otherwise-clause}.''

@node Special Symbols, Objects with Multiple Notations, Additional Uses for Indirect Definitions in Modified BNF Syntax, Notational Conventions
@subsubsection Special Symbols

The special symbols described here are used as a notational convenience
within this document, and are part of neither the @r{Common Lisp} language nor
its environment.

@table @asis

@item @result{}   
This indicates evaluation.
For example:

@example
 (+ 4 5) @result{}  9 
@end example

This means that the result of
evaluating the @i{form} @t{(+ 4 5)} is @t{9}.

If a @i{form} returns @i{multiple values}, those values might
be shown separated by spaces, line breaks, or commas.
For example:

@example
 (truncate 7 5)
@result{}  1 2
 (truncate 7 5) 
@result{}  1
   2
 (truncate 7 5)
@result{}  1, 2
@end example

Each of the above three examples is equivalent, and specifies
that @t{(truncate 7 5)} returns two values, which are @t{1} and @t{2}.

Some @i{conforming implementations} actually type an arrow (or some
other indicator) before showing return values, while others do not.

@item @i{OR}@result{}  
The notation ``{@i{OR}@result{}}'' is used to denote one of several possible
alternate results.  The example

@example
 (char-name #\a)
@result{}  NIL
@i{OR}@result{} "LOWERCASE-a"
@i{OR}@result{} "Small-A"
@i{OR}@result{} "LA01"
@end example

indicates that @b{nil}, @t{"LOWERCASE-a"}, @t{"Small-A"}, @t{"LA01"} are
among the possible results of @t{(char-name #\a)}---each with equal preference.
Unless explicitly specified otherwise, it should not be assumed that the set of possible 
results shown is exhaustive.
Formally, the above example is equivalent to

@example
 (char-name #\a) @result{}  @i{implementation-dependent}
@end example

but it is intended to provide additional information to illustrate some
of the ways in which it is permitted for implementations to diverge.

@item @i{NOT}@result{}  
The notation ``{@i{NOT}@result{}}'' is used to denote a result which is not possible.
This might be used, for example, in order to emphasize a situation where
some anticipated misconception might lead the reader to falsely believe
that the result might be possible.  For example,

@example
 (function-lambda-expression 
    (funcall #'(lambda (x) #'(lambda () x)) nil))
@result{}  NIL, @i{true}, NIL
@i{OR}@result{} (LAMBDA () X), @i{true}, NIL
@i{NOT}@result{} NIL, @i{false}, NIL
@i{NOT}@result{} (LAMBDA () X), @i{false}, NIL
@end example

@item @equiv{}  
This indicates code equivalence. For example:

@example
 (gcd x (gcd y z)) @equiv{} (gcd (gcd x y) z)
@end example

This means that the results and observable side-effects of evaluating
the @i{form}
@t{(gcd x (gcd y z))}  are always the same as the results
and observable side-effects of
@t{(gcd (gcd x y) z)}  for any 
@t{x}, @t{y}, and @t{z}.

@item {@t{ |> }}  
@r{Common Lisp} specifies input and output with respect to a non-interactive stream model.
The specific details of how interactive input and output are mapped onto that
non-interactive model are @i{implementation-defined}.

For example, @i{conforming implementations} are permitted to differ in issues 
of how interactive input is terminated.  For example, the @i{function} @b{read}
terminates when the final delimiter is typed on a non-interactive stream.
In some @i{implementations}, an interactive call to @b{read} returns
as soon as the final delimiter is typed, even if that delimiter is not a @i{newline}.
In other @i{implementations}, a final @i{newline} is always required.
In still other @i{implementations}, there might be a command which ``activates''
a buffer full of input without the command itself being visible on the program's
input stream.

In the examples in this document, the notation ``{@t{ |> }}'' precedes 
lines where interactive input and output occurs.  Within such a scenario,
``@b{|>>}@t{this notation}@b{<<|}'' notates user input.

For example, the notation

@example
 (+ 1 (print (+ (sqrt (read)) (sqrt (read)))))
@t{ |> } @b{|>>}@t{9 16 }@b{<<|}
@t{ |> } 7
@result{}  8
@end example

shows an interaction in which
  ``@t{(+ 1 (print (+ (sqrt (read)) (sqrt (read)))))}''
    is a @i{form} to be @i{evaluated},
  ``@t{9 16 }'' is interactive input,
  ``@t{7}'' is interactive output, and 
  ``@t{8}'' is the @i{value} @i{yielded} from the @i{evaluation}.

The use of this notation is intended to disguise small differences 
in interactive input and output behavior between @i{implementations}.

Sometimes, the non-interactive stream model calls for a @i{newline}.
How that @i{newline} character is interactively entered is an 
@i{implementation-defined} detail of the user interface, but in that
case, either the notation ``<@i{Newline}>'' or ``{@i{[<--}~]}'' might be used.

@example
 (progn (format t "~&Who? ") (read-line))
@t{ |> } Who? @b{|>>}@t{Fred, Mary, and Sally{@i{[<--}~]}}@b{<<|}
@result{}  "Fred, Mary, and Sally", @i{false}
@end example

@end table

@node Objects with Multiple Notations, Case in Symbols, Special Symbols, Notational Conventions
@subsubsection Objects with Multiple Notations

Some @i{objects} in @r{Common Lisp} can be notated in more than one way.
In such situations, the choice of which notation to use is technically arbitrary,
but conventions may exist which convey a ``point of view'' or ``sense of intent.''

@node Case in Symbols, Numbers (Objects with Multiple Notations), Objects with Multiple Notations, Notational Conventions
@subsubsection Case in Symbols

@ITindex{case in symbol names}

While @i{case} is significant in the process of @i{interning} a @i{symbol},
the @i{Lisp reader}, by default, attempts to canonicalize the case of a
@i{symbol} prior to interning; see @ref{Effect of Readtable Case on the Lisp Reader}.
As such, case in @i{symbols} is not, by default, significant.
Throughout this document, except as explicitly noted otherwise,
the case in which a @i{symbol} appears is not significant; 
that is, @t{HELLO}, @t{Hello}, @t{hElLo}, and @t{hello} are
all equivalent ways to denote a symbol whose name is @t{"HELLO"}.

The characters @i{backslash} and @i{vertical-bar} are used to explicitly
quote the @i{case} and other parsing-related 
aspects
of characters.  As such,
the notations @t{|hello|} and @t{\h\e\l\l\o} are equivalent ways
to refer to a symbol whose name is @t{"hello"}, and which is @i{distinct} from
any symbol whose name is @t{"HELLO"}.

The @i{symbols} that correspond to @r{Common Lisp} @i{defined names}
have @i{uppercase} names even though their names generally appear
in @i{lowercase} in this document.

@node Numbers (Objects with Multiple Notations), Use of the Dot Character, Case in Symbols, Notational Conventions
@subsubsection Numbers

Although @r{Common Lisp} provides a variety of ways for programs to manipulate the
input and output radix for rational numbers, all numbers in this document
are in decimal notation unless explicitly noted otherwise.

@node Use of the Dot Character, NIL, Numbers (Objects with Multiple Notations), Notational Conventions
@subsubsection Use of the Dot Character

The dot appearing by itself in an @i{expression} such as

@t{(@i{item1} @i{item2} @t{.} @i{tail})}

means that @i{tail} represents a @i{list} of @i{objects} 
at the end of a list.  For example,

@t{(A B C @t{.} (D E F))}

is notationally equivalent to:

@t{(A B C D E F)}

Although @i{dot} is a valid constituent character in a symbol, no 
@i{standardized} @i{symbols} contain the character @i{dot},
so a period that follows a reference to a @i{symbol} at the end of
a sentence in this document should always be interpreted as a period
and never as part of the @i{symbol}'s @i{name}.
For example, within this document, a sentence such as
 ``This sample sentence refers to the symbol @b{car}.'' 
refers to a symbol whose name is @t{"CAR"} (with three letters),
and never to a four-letter symbol @t{"CAR."}

@node NIL, Designators, Use of the Dot Character, Notational Conventions
@subsubsection NIL

@IGindex{nil}

@IGindex{()}

@IRindex{nil}

@b{nil} has a variety of meanings.
It is a @i{symbol} in the @t{COMMON-LISP} @i{package} with the @i{name} @t{"NIL"},
it is @i{boolean} (and @i{generalized boolean}) @i{false},
it is the @i{empty list},
and it is the @i{name} of the @i{empty type} (a @i{subtype} of all @i{types}).

Within @r{Common Lisp}, @b{nil} can be notated interchangeably as either @t{NIL} or @t{()}.
By convention, the choice of notation offers a hint as to which of its many
roles it is playing.

@group
@noindent
@w{  @b{For Evaluation?}  @b{Notation}  @b{Typically Implied Role}       }
@w{  ________________________________________________________}
@w{  Yes              @t{nil}       use as a @i{boolean}.            }
@w{  Yes              @t{'nil}      use as a @i{symbol}.             }
@w{  Yes              @t{'()}       use as an @i{empty list}         }
@w{  No               @t{nil}       use as a @i{symbol} or @i{boolean}.  }
@w{  No               @t{()}        use as an @i{empty list}.        }

@noindent
@w{               Figure 1--1: Notations for NIL             }

@end group

Within this document only, @b{nil} is also sometimes notated as @i{false} to
emphasize its role as a @i{boolean}.

For example:

@example
 (print ())                          ;avoided
 (defun three nil 3)                 ;avoided 
 '(nil nil)                          ;list of two symbols
 '(() ())                            ;list of empty lists
 (defun three () 3)                  ;Emphasize empty parameter list.
 (append '() '()) @result{}  ()              ;Emphasize use of empty lists
 (not nil) @result{}  @i{true}                   ;Emphasize use as Boolean false
 (get 'nil 'color)                   ;Emphasize use as a symbol
@end example

A @i{function} is sometimes said to ``be @i{false}'' or ``be @i{true}''
in some circumstance.
Since no @i{function} object can be the same as @b{nil} 
and all @i{function} @i{objects} represent @i{true} when viewed as @i{booleans},
it would be meaningless to say that the @i{function} was literally @i{false} 
and uninteresting to say that it was literally @i{true}.
Instead, these phrases are just traditional alternative ways of saying that the
@i{function} ``returns @i{false}'' or ``returns @i{true},'' respectively.

@node Designators, Nonsense Words, NIL, Notational Conventions
@subsubsection Designators

A @i{designator}
@IGindex{designator}
 is an @i{object} that denotes another @i{object}.

Where a @i{parameter} of an @i{operator} is described as a @i{designator},
the description of the @i{operator} is written in a way that assumes that
the value of the @i{parameter} is the denoted @i{object};
that is, that the @i{parameter} is already of the denoted @i{type}.
(The specific nature of the @i{object} denoted by
   a ``<<@i{type}>> @i{designator}''
or a ``@i{designator} for a <<@i{type}>>'' 
can be found in the Glossary entry for ``<<@i{type}>> @i{designator}.'')

For example, ``@b{nil}'' and ``the @i{value} of @b{*standard-output*}'' are operationally
indistinguishable as @i{stream designators}.  Similarly, 
the @i{symbol} @t{foo} and the @i{string} @t{"FOO"} 
are operationally indistinguishable as @i{string designators}.  

Except as otherwise noted, in a situation where the denoted @i{object} 
might be used multiple times, it is @i{implementation-dependent}
whether the @i{object} is coerced only once or whether the coercion occurs
each time the @i{object} must be used.

For example, @b{mapcar} receives a @i{function designator} as an argument,
and its description is written as if this were simply a function.  In fact, it
is @i{implementation-dependent} whether the @i{function designator} is 
coerced right away or whether it is carried around internally in the form that
it was given as an @i{argument} and re-coerced each time it is needed.  In most
cases, @i{conforming programs} cannot detect the distinction, but there are some 
pathological situations (particularly those involving self-redefining or 
mutually-redefining functions) which do conform and which can detect this difference.
The following program is a @i{conforming program}, but might or might not have
portably correct results, depending on whether its correctness depends on one or
the other of the results:

@example
 (defun add-some (x) 
   (defun add-some (x) (+ x 2))
   (+ x 1)) @result{}  ADD-SOME
 (mapcar 'add-some '(1 2 3 4))
@result{}  (2 3 4 5)
@i{OR}@result{} (2 4 5 6)
@end example

In a few rare situations, there may be a need in a dictionary entry
to refer to the @i{object} that was the original @i{designator}
for a @i{parameter}.
Since naming the @i{parameter} would refer to the denoted @i{object},
the phrase ``the <<@i{parameter-name}>> @i{designator}'' 
can be used to refer to the @i{designator} which was the @i{argument}
from which the @i{value} of <<@i{parameter-name}>> was computed.

@node Nonsense Words,  , Designators, Notational Conventions
@subsubsection Nonsense Words

@ICindex{foo}

@ICindex{bar}

@ICindex{baz}

@ICindex{quux}

When a word having no pre-attached semantics is required (@i{e.g.}, in an
example), it is common in the Lisp community to use one of the words
``foo,'' ``bar,'' ``baz,'' and ``quux.''  For example, in

@example
 (defun foo (x) (+ x 1))
@end example

the use of the name @t{foo} is just a shorthand way of saying 
``please substitute your favorite name here.''

These nonsense words have gained such prevalance of usage, that it is
commonplace for newcomers to the community to begin to wonder if there
is an attached semantics which they are overlooking---there is not.

@node Error Terminology, Sections Not Formally Part Of This Standard, Notational Conventions, Definitions
@subsection Error Terminology

@IGindex{error terminology}

Situations in which errors might, should, or must be signaled are described
in the standard.  The wording used to describe such situations is intended
to have precise meaning. The following list is a glossary of those meanings.

@table @asis

@item @b{Safe code}  

@IGindex{safe}

This is @i{code} processed with the @b{safety} optimization 
at its highest setting (@t{3}).  @b{safety} is a lexical property
of code.  The phrase ``the function @t{F} should signal an error'' 
means that if @t{F} is invoked from code processed with the highest
@b{safety} optimization, an error is signaled.
It is @i{implementation-dependent} whether @t{F} or the calling 
code signals the error.

@item @b{Unsafe code}  

@IGindex{unsafe}

This is code processed with lower safety levels.

Unsafe code might do error checking.  Implementations are permitted to
treat all code as safe code all the time.

@item @b{An error is signaled}  

@IGindex{signal}

@ITindex{is signaled}

@ITindex{must signal}

This means that an error is signaled in both safe and unsafe code.
@i{Conforming code} may rely on the fact that the error is signaled
in both safe and unsafe code.  Every implementation is required to
detect the error in both safe and unsafe code. For example, ``an error
is signaled if @b{unexport} is given a @i{symbol}
not @i{accessible} in the @i{current package}.''

If an explicit error type is not specified, the default is @b{error}.

@item @b{An error should be signaled}  

@IGindex{signal}

@ITindex{should signal}

This means that an error is signaled in safe code, and an error
might be signaled in unsafe code.  @i{Conforming code} may rely on the
fact that the error is signaled in safe code.  Every
implementation is required to detect the error at least in safe code.
When the error is not signaled, the ``consequences are undefined''
(see below).  For example, ``@b{+} should signal an error of @i{type} @b{type-error}
if any argument is not of @i{type} @b{number}.''

@item @b{Should be prepared to signal an error}  

@IGindex{signal}

@ITindex{prepared to signal}

This is similar to ``should be signaled'' except that it does not
imply that `extra effort' has to be taken on the part of an @i{operator}
to discover an erroneous situation if the normal action of that @i{operator}
can be performed successfully with only `lazy' checking.
An @i{implementation} is always permitted to signal an error,
but even in @i{safe} @i{code}, it is only required to signal the error
when failing to signal it might lead to incorrect results.
In @i{unsafe} @i{code}, the consequences are undefined.

For example, defining that 
 ``@b{find} should be prepared to signal an error of @i{type} @b{type-error}
   if its second @i{argument} is not a @i{proper list}''
does not imply that an error is always signaled.  The @i{form}

@example
 (find 'a '(a b . c))
@end example

must either signal an error of @i{type} @b{type-error} in @i{safe} @i{code},
else return @t{A}.
In @i{unsafe} @i{code}, the consequences are undefined.
By contrast,

@example
 (find 'd '(a b . c))
@end example

must signal an error of @i{type} @b{type-error} in @i{safe} @i{code}.
In @i{unsafe} @i{code}, the consequences are undefined.
Also,

@example
 (find 'd '#1=(a b . #1#))
@end example

in @i{safe code}
   might return @b{nil} (as an @i{implementation-defined} extension),
   might never return,
or might signal an error of @i{type} @b{type-error}.
In @i{unsafe} @i{code}, the consequences are undefined.

Typically, the ``should be prepared to signal'' terminology is used in
type checking situations where there are efficiency considerations that
make it impractical to detect errors that are not relevant to the
correct operation of the @i{operator}.

@item @b{The consequences are unspecified}  

@ITindex{consequences}

@ITindex{unspecified consequences}

This means that the consequences are unpredictable but harmless.
Implementations are permitted to specify the consequences of this
situation. No @i{conforming code} may depend on the results or effects of
this situation, and all @i{conforming code} is required to treat the
results and effects of this situation as unpredictable but harmless.
For example, ``if the second argument to @b{shared-initialize}
specifies a name that does not correspond to any @i{slots}
@i{accessible} in the @i{object}, the results are unspecified.''

@item @b{The consequences are undefined}  

@ITindex{consequences}

@ITindex{undefined consequences}

This means that the consequences are unpredictable. The consequences
may range from harmless to fatal.  No @i{conforming code} may depend on
the results or effects. @i{Conforming code} must treat the consequences as
unpredictable.  In places where the words ``must,'' ``must not,'' or
``may not'' are used, then ``the consequences are undefined'' if the
stated requirement is not met and no specific consequence is
explicitly stated.  An implementation is permitted to signal an error
in this case.

For example: ``Once a name has been declared by @b{defconstant}
to be constant, any further assignment or binding of that
variable has undefined consequences.''

@item @b{An error might be signaled}  

@IGindex{signal}

@ITindex{might signal}

This means that the situation has undefined consequences;
however, if an error is signaled, it is of the specified @i{type}.
For example, ``@b{open} might signal an error of @i{type} @b{file-error}.''

@item @b{The return values are unspecified}  

@ITindex{unspecified values}

This means that only the number and nature of the return values of a
@i{form} are not specified.  However, the issue of whether or not
any side-effects or transfer of control occurs is still well-specified.

A program can be well-specified even if it uses a function whose
returns values are unspecified.  For example, even if the return
values of some function @t{F} are unspecified, an expression such as
@t{(length (list (F)))} is still well-specified because it does not
rely on any particular aspect of the value or values returned by @t{F}.

@item @b{Implementations may be extended to cover this situation}  

@ITindex{extensions}

This means that the @i{situation} has undefined consequences;
however, a @i{conforming implementation} is free to treat
the situation in a more specific way.  
For example, an @i{implementation} might define 
    that      an error is signaled,
 or that      an error should be signaled,
 or even that a certain well-defined non-error behavior occurs.

No @i{conforming code} may depend on the consequences of such a @i{situation};
all @i{conforming code} must treat the consequences of the situation
as undefined. @i{Implementations} are required to document how the
situation is treated.

For example, ``implementations may be extended to define other type
specifiers to have a corresponding @i{class}.''

@item @b{Implementations are free to extend the syntax}  

@ITindex{extensions}

This means that in this situation implementations are permitted to
define unambiguous extensions to the syntax of the @i{form} being
described.  No @i{conforming code} may depend on this extension.
Implementations are required to document each such extension. All
@i{conforming code} is required to treat the syntax as meaningless. The
standard might disallow certain extensions while allowing others. For
example, ``no implementation is free to extend the syntax of
@b{defclass}.''

@item @b{A warning might be issued}  

@ITindex{warning}

This means that @i{implementations} are encouraged to issue a warning
if the context is appropriate (@i{e.g.}, when compiling).  However, a
@i{conforming implementation} is not required to issue a warning.

@end table

@node Sections Not Formally Part Of This Standard, Interpreting Dictionary Entries, Error Terminology, Definitions
@subsection Sections Not Formally Part Of This Standard

Front matter and back matter, such as the ``Table of Contents,'' 
``Index,'' ``Figures,'' ``Credits,'' and ``Appendix'' are not considered formally 
part of this standard, so that we retain the flexibility needed to update
these sections even at the last minute without fear of needing a formal 
vote to change those parts of the document.  These items are quite short 
and very useful, however, and it is not recommended that they be removed 
even in an abridged version of this document.

Within the concept sections, subsections whose names begin with 
the words ``Note'' or ``Notes'' or ``Example'' or ``Examples'' 
are provided for illustration purposes only, and are not considered
part of the standard.

An attempt has been made to place these sections last in their parent section,
so that they could be removed without disturbing the contiguous numbering of the 
surrounding sections in order to produce a document of smaller size.

Likewise, the ``Examples'' and ``Notes'' sections in a dictionary entry
are not considered part of the standard and could be removed if necessary.

Nevertheless, the examples provide important clarifications and consistency 
checks for the rest of the material, and such abridging is not recommended
unless absolutely unavoidable.

@node Interpreting Dictionary Entries,  , Sections Not Formally Part Of This Standard, Definitions
@subsection Interpreting Dictionary Entries

The dictionary entry for each @i{defined name} is partitioned into
sections.  Except as explicitly indicated otherwise below, each section
is introduced by a label identifying that section.  The omission of a
section implies that the section is either not applicable, or would
provide no interesting information.

This section defines the significance of each potential section in a
dictionary entry.

@menu
* The ``Affected By'' Section of a Dictionary Entry::  
* The ``Arguments'' Section of a Dictionary Entry::  
* The ``Arguments and Values'' Section of a Dictionary Entry::	
* The ``Binding Types Affected'' Section of a Dictionary Entry::  
* The ``Class Precedence List'' Section of a Dictionary Entry::	 
* Dictionary Entries for Type Specifiers::  
* The ``Compound Type Specifier Kind'' Section of a Dictionary Entry::	
* The ``Compound Type Specifier Syntax'' Section of a Dictionary Entry::  
* The ``Compound Type Specifier Arguments'' Section of a Dictionary Entry::  
* The ``Compound Type Specifier Description'' Section of a Dictionary Entry::  
* The ``Constant Value'' Section of a Dictionary Entry::  
* The ``Description'' Section of a Dictionary Entry::  
* The ``Examples'' Section of a Dictionary Entry::  
* The ``Exceptional Situations'' Section of a Dictionary Entry::  
* The ``Initial Value'' Section of a Dictionary Entry::	 
* The ``Argument Precedence Order'' Section of a Dictionary Entry::  
* The ``Method Signature'' Section of a Dictionary Entry::  
* The ``Name'' Section of a Dictionary Entry::	
* The ``Notes'' Section of a Dictionary Entry::	 
* The ``Pronunciation'' Section of a Dictionary Entry::	 
* The ``See Also'' Section of a Dictionary Entry::  
* The ``Side Effects'' Section of a Dictionary Entry::	
* The ``Supertypes'' Section of a Dictionary Entry::  
* The ``Syntax'' Section of a Dictionary Entry::  
* Special ``Syntax'' Notations for Overloaded Operators::  
* Naming Conventions for Rest Parameters::  
* Requiring Non-Null Rest Parameters in the ``Syntax'' Section::  
* Return values in the ``Syntax'' Section::  
* No Arguments or Values in the ``Syntax'' Section::  
* Unconditional Transfer of Control in the ``Syntax'' Section::	 
* The ``Valid Context'' Section of a Dictionary Entry::	 
* The ``Value Type'' Section of a Dictionary Entry::  
@end menu

@node The ``Affected By'' Section of a Dictionary Entry, The ``Arguments'' Section of a Dictionary Entry, Interpreting Dictionary Entries, Interpreting Dictionary Entries
@subsubsection The ``Affected By'' Section of a Dictionary Entry

For an @i{operator}, anything that can affect the side effects of
or @i{values} returned by the @i{operator}.

For a @i{variable}, anything that can affect the @i{value} of the @i{variable}
including @i{functions} that bind or assign it.

@node The ``Arguments'' Section of a Dictionary Entry, The ``Arguments and Values'' Section of a Dictionary Entry, The ``Affected By'' Section of a Dictionary Entry, Interpreting Dictionary Entries
@subsubsection The ``Arguments'' Section of a Dictionary Entry

This information describes the syntax information of entries such as those for
@i{declarations} and special @i{expressions} which are never @i{evaluated}
as @i{forms}, and so do not return @i{values}.

@node The ``Arguments and Values'' Section of a Dictionary Entry, The ``Binding Types Affected'' Section of a Dictionary Entry, The ``Arguments'' Section of a Dictionary Entry, Interpreting Dictionary Entries
@subsubsection The ``Arguments and Values'' Section of a Dictionary Entry

An English language description of what @i{arguments} the @i{operator} accepts
and what @i{values} it returns, including information about defaults for @i{parameters}
corresponding to omittable @i{arguments}
(such as @i{optional parameters} and @i{keyword parameters}).
For @i{special operators} and @i{macros},
their @i{arguments} are not @i{evaluated} unless it is explicitly stated in their
descriptions that they are @i{evaluated}.

@node The ``Binding Types Affected'' Section of a Dictionary Entry, The ``Class Precedence List'' Section of a Dictionary Entry, The ``Arguments and Values'' Section of a Dictionary Entry, Interpreting Dictionary Entries
@subsubsection The ``Binding Types Affected'' Section of a Dictionary Entry

This information alerts the reader to the kinds of @i{bindings} that might 
potentially be affected by a declaration.  Whether in fact any particular such
@i{binding} is actually affected is dependent on additional factors as well.
See the ``Description'' section of the declaration in question for details.

@node The ``Class Precedence List'' Section of a Dictionary Entry, Dictionary Entries for Type Specifiers, The ``Binding Types Affected'' Section of a Dictionary Entry, Interpreting Dictionary Entries
@subsubsection The ``Class Precedence List'' Section of a Dictionary Entry

This appears in the dictionary entry for a @i{class},
and contains an ordered list of the @i{classes} defined 
by @r{Common Lisp} that must be in the @i{class precedence list} of this @i{class}.

It is permissible for other (@i{implementation-defined}) @i{classes}
to appear in the @i{implementation}'s @i{class precedence list} for the @i{class}.

It is permissible for 
  either @b{standard-object}
      or @b{structure-object}
to appear in the @i{implementation}'s @i{class precedence list};
for details, see @ref{Type Relationships}.

Except as explicitly indicated otherwise somewhere in this specification,
no additional @i{standardized} @i{classes} may appear in 
the @i{implementation}'s @i{class precedence list}.

By definition of the relationship between @i{classes} and @i{types},
the @i{classes} listed in this section are also @i{supertypes} of 
the @i{type} denoted by the @i{class}.

@node Dictionary Entries for Type Specifiers, The ``Compound Type Specifier Kind'' Section of a Dictionary Entry, The ``Class Precedence List'' Section of a Dictionary Entry, Interpreting Dictionary Entries
@subsubsection Dictionary Entries for Type Specifiers

The @i{atomic type specifiers} are those @i{defined names} 
listed in @i{Figure~4--2}.
Such dictionary entries are of kind 
``Class,'' ``Condition Type,'' ``System Class,'' or ``Type.''
A description of how to interpret 
a @i{symbol} naming one of these @i{types} or @i{classes} 
as an @i{atomic type specifier}
is found in the ``Description'' section of such dictionary entries.

The @i{compound type specifiers} are those @i{defined names} 
listed in @i{Figure~4--3}.
Such dictionary entries are of kind ``Class,'' ``System Class,''
``Type,'' or ``Type Specifier.''
A description of how to interpret as a @i{compound type specifier}
a @i{list} whose @i{car} is such a @i{symbol}
is found in the 
     ``Compound Type Specifier Kind,''
     ``Compound Type Specifier Syntax,''
     ``Compound Type Specifier Arguments,''
 and ``Compound Type Specifier Description''
sections of such dictionary entries.

@node The ``Compound Type Specifier Kind'' Section of a Dictionary Entry, The ``Compound Type Specifier Syntax'' Section of a Dictionary Entry, Dictionary Entries for Type Specifiers, Interpreting Dictionary Entries
@subsubsection The ``Compound Type Specifier Kind'' Section of a Dictionary Entry

An ``abbreviating'' @i{type specifier} is one that describes a @i{subtype}
for which it is in principle possible to enumerate the @i{elements},
but for which in practice it is impractical to do so.

A ``specializing'' @i{type specifier} is one that describes a @i{subtype}
by restricting the @i{type} of one or more components of the @i{type},
such as @i{element type} or @i{complex part type}.

A ``predicating'' @i{type specifier} is one that describes a @i{subtype}
containing only those @i{objects} that satisfy a given @i{predicate}.

A ``combining'' @i{type specifier} is one that describes a @i{subtype}
in a compositional way, using combining operations (such as ``and,'' ``or,'' and
``not'') on other @i{types}.

@node The ``Compound Type Specifier Syntax'' Section of a Dictionary Entry, The ``Compound Type Specifier Arguments'' Section of a Dictionary Entry, The ``Compound Type Specifier Kind'' Section of a Dictionary Entry, Interpreting Dictionary Entries
@subsubsection The ``Compound Type Specifier Syntax'' Section of a Dictionary Entry

This information about a @i{type} describes the syntax of a 
@i{compound type specifier} for that @i{type}.

Whether or not the @i{type} is acceptable as an @i{atomic type specifier}
is not represented here; see @ref{Dictionary Entries for Type Specifiers}.

@node The ``Compound Type Specifier Arguments'' Section of a Dictionary Entry, The ``Compound Type Specifier Description'' Section of a Dictionary Entry, The ``Compound Type Specifier Syntax'' Section of a Dictionary Entry, Interpreting Dictionary Entries
@subsubsection The ``Compound Type Specifier Arguments'' Section of a Dictionary Entry

This information describes @i{type} information for the structures defined in
the ``Compound Type Specifier Syntax'' section.

@node The ``Compound Type Specifier Description'' Section of a Dictionary Entry, The ``Constant Value'' Section of a Dictionary Entry, The ``Compound Type Specifier Arguments'' Section of a Dictionary Entry, Interpreting Dictionary Entries
@subsubsection The ``Compound Type Specifier Description'' Section of a Dictionary Entry

This information describes the meaning of the structures defined in
the ``Compound Type Specifier Syntax'' section.

@node The ``Constant Value'' Section of a Dictionary Entry, The ``Description'' Section of a Dictionary Entry, The ``Compound Type Specifier Description'' Section of a Dictionary Entry, Interpreting Dictionary Entries
@subsubsection The ``Constant Value'' Section of a Dictionary Entry

This information describes the unchanging @i{type} and @i{value} of 
a @i{constant variable}.

@node The ``Description'' Section of a Dictionary Entry, The ``Examples'' Section of a Dictionary Entry, The ``Constant Value'' Section of a Dictionary Entry, Interpreting Dictionary Entries
@subsubsection The ``Description'' Section of a Dictionary Entry

A summary of the @i{operator} and all intended aspects of the @i{operator}, 
but does not necessarily include all the fields referenced below it 
(``Side Effects,'' ``Exceptional Situations,'' @i{etc.})

@node The ``Examples'' Section of a Dictionary Entry, The ``Exceptional Situations'' Section of a Dictionary Entry, The ``Description'' Section of a Dictionary Entry, Interpreting Dictionary Entries
@subsubsection The ``Examples'' Section of a Dictionary Entry

Examples of use of the @i{operator}.
These examples are not considered part of the standard;
see @ref{Sections Not Formally Part Of This Standard}.

@node The ``Exceptional Situations'' Section of a Dictionary Entry, The ``Initial Value'' Section of a Dictionary Entry, The ``Examples'' Section of a Dictionary Entry, Interpreting Dictionary Entries
@subsubsection The ``Exceptional Situations'' Section of a Dictionary Entry

  Three kinds of information may appear here:
@table @asis

@item @t{*}  
Situations that are detected by the @i{function} and formally signaled.
@item @t{*}  
Situations that are handled by the @i{function}.
@item @t{*}  
Situations that may be detected by the @i{function}.
@end table

This field does not include conditions that could
be signaled by @i{functions} passed to and called by this @i{operator}
as arguments or through dynamic variables, nor by executing subforms of this
operator if it is a @i{macro} or @i{special operator}.

@node The ``Initial Value'' Section of a Dictionary Entry, The ``Argument Precedence Order'' Section of a Dictionary Entry, The ``Exceptional Situations'' Section of a Dictionary Entry, Interpreting Dictionary Entries
@subsubsection The ``Initial Value'' Section of a Dictionary Entry

This information describes the initial @i{value} of a @i{dynamic variable}.
Since this variable might change, see @i{type} restrictions in the ``Value Type'' section.

@node The ``Argument Precedence Order'' Section of a Dictionary Entry, The ``Method Signature'' Section of a Dictionary Entry, The ``Initial Value'' Section of a Dictionary Entry, Interpreting Dictionary Entries
@subsubsection The ``Argument Precedence Order'' Section of a Dictionary Entry

This information describes the argument precedence order.
If it is omitted, the argument precedence order is the default (left to right).

@node The ``Method Signature'' Section of a Dictionary Entry, The ``Name'' Section of a Dictionary Entry, The ``Argument Precedence Order'' Section of a Dictionary Entry, Interpreting Dictionary Entries
@subsubsection The ``Method Signature'' Section of a Dictionary Entry

The description of a @i{generic function} includes descriptions of the
@i{methods} that are defined on that @i{generic function} by the standard.  
A method signature is used to describe the @i{parameters} and 
@i{parameter specializers} for each @i{method}. 
@i{Methods} defined for the @i{generic function} must be of the form described
by the @i{method} @i{signature}. 

@code{F}  @i{@r{(}@i{x} @i{class}@r{)}
	      @r{(}@i{y} t@r{)}
	      {&optional} @i{z} {&key} @i{k}}

@noindent
This @i{signature} indicates that this method on the @i{generic function}
@b{F} has two @i{required parameters}:
     @i{x}, which must be a @i{generalized instance} of the @i{class} @i{class};
 and @i{y}, which can  be any @i{object} 
       (@i{i.e.}, a @i{generalized instance} of the @i{class} @b{t}).
In addition, there is an @i{optional parameter} @i{z} and a
@i{keyword parameter} @i{k}.  This @i{signature} also indicates that this
method on @t{F} is a @i{primary method} and has no @i{qualifiers}.

For each @i{parameter}, the @i{argument} supplied must be in the
intersection of the @i{type} specified in the description of the
corresponding @i{generic function} and the @i{type} given in 
the @i{signature} of some @i{method} (including not only those 
@i{methods} defined in this specification, but also
@i{implementation-defined} or user-defined @i{methods} in situations
where the definition of such @i{methods} is permitted).

@node The ``Name'' Section of a Dictionary Entry, The ``Notes'' Section of a Dictionary Entry, The ``Method Signature'' Section of a Dictionary Entry, Interpreting Dictionary Entries
@subsubsection The ``Name'' Section of a Dictionary Entry

This section introduces the dictionary entry.  It is not explicitly labeled.
It appears preceded and followed by a horizontal bar.

In large print at left, the @i{defined name} appears; if more than one
@i{defined name} is to be described by the entry, all such @i{names} 
are shown separated by commas.

In somewhat smaller italic print at right is an indication of what kind
of dictionary entry this is.  Possible values are:

@table @asis

@item @i{Accessor}  
This is an @i{accessor} @i{function}.

@item @i{Class}  
This is a @i{class}.

@item @i{Condition Type}  
This is a @i{subtype} of @i{type} @b{condition}.

@item @i{Constant Variable}  
This is a @i{constant variable}.

@item @i{Declaration}  
This is a @i{declaration identifier}.

@item @i{Function}  
This is a @i{function}.

@item @i{Local Function}  
This is a @i{function} that is defined only lexically within the scope of some
other @i{macro form}.

@item @i{Local Macro}  
This is a @i{macro} that is defined only lexically within the scope of some
other @i{macro form}.

@item @i{Macro}  
This is a @i{macro}.

@item @i{Restart}  
This is a @i{restart}.

@item @i{Special Operator}  
This is a @i{special operator}.

@item @i{Standard Generic Function}  
This is a @i{standard generic function}.

@item @i{Symbol}  
This is a @i{symbol} that is specially recognized in some particular situation,
such as the syntax of a @i{macro}.

@item @i{System Class}  
This is like @i{class}, but it identifies a @i{class} that is potentially
a @i{built-in class}.  (No @i{class} is actually required to be a
@i{built-in class}.)

@item @i{Type}  
This is an @i{atomic type specifier},
and depending on information for each particular entry,
may subject to form other @i{type specifiers}.

@item @i{Type Specifier}  
This is a @i{defined name} that is not an @i{atomic type specifier},
but that can be used in constructing valid @i{type specifiers}.

@item @i{Variable}  
This is a @i{dynamic variable}.

@end table

@node The ``Notes'' Section of a Dictionary Entry, The ``Pronunciation'' Section of a Dictionary Entry, The ``Name'' Section of a Dictionary Entry, Interpreting Dictionary Entries
@subsubsection The ``Notes'' Section of a Dictionary Entry

Information not found elsewhere in this description
which pertains to this @i{operator}.
Among other things, this might include 
 cross reference information,
 code equivalences, 
 stylistic hints,
 implementation hints,
 typical uses.
This information is not considered part of the standard;
any @i{conforming implementation} or @i{conforming program}
is permitted to ignore the presence of this information.

@node The ``Pronunciation'' Section of a Dictionary Entry, The ``See Also'' Section of a Dictionary Entry, The ``Notes'' Section of a Dictionary Entry, Interpreting Dictionary Entries
@subsubsection The ``Pronunciation'' Section of a Dictionary Entry

This offers a suggested pronunciation for @i{defined names} 
so that people not in verbal communication with the original designers
can figure out how to pronounce words that are not in normal English usage.
This information is advisory only, and is not considered part of the standard.
For brevity, it is only provided for entries with names that are specific to
@r{Common Lisp} and would not be found in {Webster's Third New International Dictionary
 the English Language, Unabridged}.

@node The ``See Also'' Section of a Dictionary Entry, The ``Side Effects'' Section of a Dictionary Entry, The ``Pronunciation'' Section of a Dictionary Entry, Interpreting Dictionary Entries
@subsubsection The ``See Also'' Section of a Dictionary Entry

List of references to other parts of this standard
that offer information relevant to this @i{operator}. 
This list is not part of the standard.

@node The ``Side Effects'' Section of a Dictionary Entry, The ``Supertypes'' Section of a Dictionary Entry, The ``See Also'' Section of a Dictionary Entry, Interpreting Dictionary Entries
@subsubsection The ``Side Effects'' Section of a Dictionary Entry

Anything that is changed as a result of the
evaluation of the @i{form} containing this @i{operator}.

@node The ``Supertypes'' Section of a Dictionary Entry, The ``Syntax'' Section of a Dictionary Entry, The ``Side Effects'' Section of a Dictionary Entry, Interpreting Dictionary Entries
@subsubsection The ``Supertypes'' Section of a Dictionary Entry

This appears in the dictionary entry for a @i{type},
and contains a list of the @i{standardized} @i{types} 
that must be @i{supertypes} of this @i{type}.

In @i{implementations} where there is a corresponding @i{class},
the order of the @i{classes} in the @i{class precedence list} 
is consistent with the order presented in this section.

@node The ``Syntax'' Section of a Dictionary Entry, Special ``Syntax'' Notations for Overloaded Operators, The ``Supertypes'' Section of a Dictionary Entry, Interpreting Dictionary Entries
@subsubsection The ``Syntax'' Section of a Dictionary Entry

This section describes how to use the @i{defined name} in code.
The ``Syntax'' description for a @i{generic function} 
describes the @i{lambda list} of the @i{generic function} itself, 
while the ``Method Signatures'' describe the @i{lambda lists} 
of the defined @i{methods}.
The ``Syntax'' description for 
     an @i{ordinary function},
     a @i{macro},
  or a @i{special operator}
describes its @i{parameters}.

For example, an @i{operator} description might say:

@code{F}  @i{x y {&optional} z {&key} k}

@noindent
This description indicates that the function @b{F} 
has two required parameters, @i{x} and @i{y}.  In addition,
there is an optional parameter @i{z} and a keyword parameter @i{k}.

For @i{macros} and @i{special operators}, syntax is given 
in modified BNF notation; see @ref{Modified BNF Syntax}.
For @i{functions} a @i{lambda list} is given.
In both cases, however, the outermost parentheses are omitted,
and default value information is omitted.

@node Special ``Syntax'' Notations for Overloaded Operators, Naming Conventions for Rest Parameters, The ``Syntax'' Section of a Dictionary Entry, Interpreting Dictionary Entries
@subsubsection Special ``Syntax'' Notations for Overloaded Operators

If two descriptions exist for the same operation but with different numbers of
arguments, then the extra arguments are to be treated as optional.  For example,
this pair of lines:

@code{file-position}  @i{stream} @result{}  @i{position}

@code{file-position}  @i{stream position-spec} @result{}  @i{success-p}

@noindent
is operationally equivalent to this line:

@code{file-position}  @i{stream {&optional} position-spec} @result{}  @i{result}

@noindent
and differs only in that it provides on opportunity to introduce different
names for @i{parameter} and @i{values} for each case.
The separated (multi-line) notation is used when an @i{operator} is overloaded in
such a way that the @i{parameters} are used in different ways
depending on how many @i{arguments} are supplied (@i{e.g.}, for the @i{function} @b{/})
or the return values are different in the two cases (@i{e.g.}, for the @i{function} @b{file-position}).

@node Naming Conventions for Rest Parameters, Requiring Non-Null Rest Parameters in the ``Syntax'' Section, Special ``Syntax'' Notations for Overloaded Operators, Interpreting Dictionary Entries
@subsubsection Naming Conventions for Rest Parameters

Within this specification, 
if the name of a @i{rest parameter} is chosen to be a plural noun,
use of that name in @i{parameter} font refers
to the @i{list} to which the @i{rest parameter} is bound.
Use of the singular form of that name in @i{parameter} font refers 
to an @i{element} of that @i{list}.

For example, given a syntax description such as:

@code{F}  @i{{&rest} @i{arguments}}

@noindent
it is appropriate to refer either to the @i{rest parameter} named
@i{arguments} by name, or to one of its elements by speaking of ``an @i{argument},''
``some @i{argument},'' ``each @i{argument}'' @i{etc.}

@node Requiring Non-Null Rest Parameters in the ``Syntax'' Section, Return values in the ``Syntax'' Section, Naming Conventions for Rest Parameters, Interpreting Dictionary Entries
@subsubsection Requiring Non-Null Rest Parameters in the ``Syntax'' Section

In some cases it is useful to refer to all arguments equally as a single
aggregation using a @i{rest parameter} while at the same time
requiring at least one argument.  A variety of imperative and
declarative means are available in @i{code} for expressing such a
restriction, however they generally do not manifest themselves in a
@i{lambda list}.  For descriptive purposes within this specification,

@code{F}  @i{{&rest} arguments^+}

@noindent
means the same as

@code{F}  @i{{&rest} arguments}

@noindent
but introduces the additional requirement that there be 
at least one @i{argument}.

@node Return values in the ``Syntax'' Section, No Arguments or Values in the ``Syntax'' Section, Requiring Non-Null Rest Parameters in the ``Syntax'' Section, Interpreting Dictionary Entries
@subsubsection Return values in the ``Syntax'' Section

An evaluation arrow ``{@result{} }'' precedes a list of @i{values} to be returned.
For example:

@code{F}  @i{a b c} @result{}  @i{x}

@noindent
indicates that @t{F} is an operator that has three @i{required parameters}
(@i{i.e.}, @i{a}, @i{b}, and @i{c}) and that returns one @i{value} (@i{i.e.}, @i{x}).
If more than one @i{value} is returned by an operator, the @i{names} of the
@i{values} are separated by commas, as in:

@code{F}  @i{a b c} @result{}  @i{x, y, z}

@node No Arguments or Values in the ``Syntax'' Section, Unconditional Transfer of Control in the ``Syntax'' Section, Return values in the ``Syntax'' Section, Interpreting Dictionary Entries
@subsubsection No Arguments or Values in the ``Syntax'' Section

If no @i{arguments} are permitted, or no @i{values} are returned, 
a special notation is used to make this more visually apparent.  For example,

@code{F}  @i{<@i{no @i{arguments}}>} @result{}  @i{<@i{no @i{values}}>}

indicates that @t{F} is an operator that accepts no @i{arguments} and returns
no @i{values}.

@node Unconditional Transfer of Control in the ``Syntax'' Section, The ``Valid Context'' Section of a Dictionary Entry, No Arguments or Values in the ``Syntax'' Section, Interpreting Dictionary Entries
@subsubsection Unconditional Transfer of Control in the ``Syntax'' Section

Some @i{operators} perform an unconditional transfer of control, and
so never have any return values.  Such @i{operators} are notated using
a notation such as the following:

@code{F}  @i{a b c} 
       @result{}  #<NoValue>

@node The ``Valid Context'' Section of a Dictionary Entry, The ``Value Type'' Section of a Dictionary Entry, Unconditional Transfer of Control in the ``Syntax'' Section, Interpreting Dictionary Entries
@subsubsection The ``Valid Context'' Section of a Dictionary Entry

This information is used by dictionary entries such as ``Declarations''
in order to restrict the context in which the declaration may appear.

A given ``Declaration'' might appear in 
     a @i{declaration} (@i{i.e.}, a @b{declare} @i{expression}),
     a @i{proclamation} (@i{i.e.}, a @b{declaim} or @b{proclaim} @i{form}),
  or both.

@node The ``Value Type'' Section of a Dictionary Entry,  , The ``Valid Context'' Section of a Dictionary Entry, Interpreting Dictionary Entries
@subsubsection The ``Value Type'' Section of a Dictionary Entry

This information describes any @i{type} restrictions on a @i{dynamic variable}.

@c end of including concept-definitions

@node Conformance, Language Extensions, Definitions, Introduction (Introduction)
@section Conformance

@c including concept-conformance

This standard presents the syntax and semantics to be implemented by a
@i{conforming implementation} (and its accompanying documentation).
In addition, it imposes requirements on @i{conforming programs}.

@menu
* Conforming Implementations::	
* Conforming Programs::		
@end menu

@node Conforming Implementations, Conforming Programs, Conformance, Conformance
@subsection Conforming Implementations

A @i{conforming implementation}
@IGindex{conforming implementation}
 shall adhere to the requirements outlined
in this section.

@menu
* Required Language Features::	
* Documentation of Implementation-Dependent Features::	
* Documentation of Extensions::	 
* Treatment of Exceptional Situations::	 
* Resolution of Apparent Conflicts in Exceptional Situations::	
* Examples of Resolution of Apparent Conflict in Exceptional Situations::  
* Conformance Statement::	
@end menu

@node Required Language Features, Documentation of Implementation-Dependent Features, Conforming Implementations, Conforming Implementations
@subsubsection Required Language Features

A @i{conforming implementation} shall accept all features 
(including deprecated features)
of the language specified in this standard,
with the meanings defined in this standard.

A @i{conforming implementation} shall not require the inclusion of substitute
or additional language elements in code in order to accomplish a feature of
the language that is specified in this standard.

@node Documentation of Implementation-Dependent Features, Documentation of Extensions, Required Language Features, Conforming Implementations
@subsubsection Documentation of Implementation-Dependent Features

A @i{conforming implementation} shall be accompanied by a document
that provides a definition of all @i{implementation-defined}
aspects of the language defined by this specification.

In addition, a @i{conforming implementation} is encouraged (but not required) 
to document items in this standard that are identified as
@i{implementation-dependent}, although in some cases
such documentation might simply identify the item as ``undefined.''

@node Documentation of Extensions, Treatment of Exceptional Situations, Documentation of Implementation-Dependent Features, Conforming Implementations
@subsubsection Documentation of Extensions

A @i{conforming implementation} shall be accompanied by a
document that separately describes any features accepted by the
@i{implementation} that are not specified in this standard, but that do not
cause any ambiguity or contradiction when added to the language
standard.  Such extensions shall be described as being ``extensions to
@r{Common Lisp} as specified by ANSI <<@i{standard number}>>.''

@node Treatment of Exceptional Situations, Resolution of Apparent Conflicts in Exceptional Situations, Documentation of Extensions, Conforming Implementations
@subsubsection Treatment of Exceptional Situations

A @i{conforming implementation} shall treat exceptional situations 
in a manner consistent with this specification.

@node Resolution of Apparent Conflicts in Exceptional Situations, Examples of Resolution of Apparent Conflict in Exceptional Situations, Treatment of Exceptional Situations, Conforming Implementations
@subsubsection Resolution of Apparent Conflicts in Exceptional Situations

If more than one passage in this specification appears to apply to the
same situation but in conflicting ways, the passage that appears
to describe the situation in the most specific way (not necessarily the
passage that provides the most constrained kind of error detection) 
takes precedence.

@node Examples of Resolution of Apparent Conflict in Exceptional Situations, Conformance Statement, Resolution of Apparent Conflicts in Exceptional Situations, Conforming Implementations
@subsubsection Examples of Resolution of Apparent Conflict in Exceptional Situations

Suppose that function @t{foo} is a member of a set S of @i{functions} that
operate on numbers.  Suppose that one passage states that an error must be
signaled if any @i{function} in S is ever given an argument of @t{17}.
Suppose that an apparently conflicting passage states that the consequences 
are undefined if @t{foo} receives an argument of @t{17}.  Then the second passage
(the one specifically about @t{foo}) would dominate because the description of
the situational context is the most specific, and it would not be required that
@t{foo} signal an error on an argument of @t{17} even though other functions in 
the set S would be required to do so.

@node Conformance Statement,  , Examples of Resolution of Apparent Conflict in Exceptional Situations, Conforming Implementations
@subsubsection Conformance Statement

A @i{conforming implementation} shall produce a conformance statement 
as a consequence of using the implementation, or that statement
shall be included in the accompanying documentation.  If the implementation
conforms in all respects with this standard, the conformance statement
shall be

@table @asis

@item @t{}  
``<<@i{Implementation}>> conforms with the requirements 
	  of ANSI <<@i{standard number}>>''
@end table

If the @i{implementation} conforms with some but not all of the requirements of this
standard, then the conformance statement shall be

@table @asis

@item @t{}  
``<<@i{Implementation}>> conforms with the requirements of
	  ANSI <<@i{standard number}>> with the following exceptions: 
	  <<@i{reference to or complete list of the requirements of
		   the standard with which the implementation does not conform}>>.''
@end table

@node Conforming Programs,  , Conforming Implementations, Conformance
@subsection Conforming Programs

@IGindex{conforming program}

@IGindex{conforming code}

Code conforming with the requirements of this standard shall adhere to the
following:

@table @asis

@item 1.  
@i{Conforming code} shall use only those features of the
               language syntax and semantics that are 
	       either specified in this standard
		   or defined using the extension mechanisms 
		      specified in the standard.

@item 2.  
@i{Conforming code} shall not rely on any particular
              interpretation of @i{implementation-dependent} features.

@item 3.  
@i{Conforming code} shall not depend on the consequences
	      of undefined or unspecified situations.

@item 4.  
@i{Conforming code} does not use any constructions 
	      that are prohibited by the standard.

@item 5.  
@i{Conforming code} does not depend on extensions 
	      included in an implementation.
@end table

@menu
* Use of Implementation-Defined Language Features::  
* Use of Read-Time Conditionals::  
@end menu

@node Use of Implementation-Defined Language Features, Use of Read-Time Conditionals, Conforming Programs, Conforming Programs
@subsubsection Use of Implementation-Defined Language Features

Note that @i{conforming code} may rely on particular
@i{implementation-defined} values or features. Also note that the
requirements for @i{conforming code} and @i{conforming implementations} do not
require that the results produced by conforming code always be the
same when processed by a @i{conforming implementation}. The results may be the
same, or they may differ.

@i{Portable code} is written using only @i{standard characters}.

Conforming code may run in all conforming implementations, but might
have allowable @i{implementation-defined} behavior that makes it
non-portable code.
For example, the following are examples of @i{forms} that are conforming, but
that might return different @i{values} in different implementations:

@example
 (evenp most-positive-fixnum) @result{}  @i{implementation-dependent}
 (random) @result{}  @i{implementation-dependent}
 (> lambda-parameters-limit 93) @result{}  @i{implementation-dependent}
 (char-name #\A) @result{}  @i{implementation-dependent}
@end example

@node Use of Read-Time Conditionals,  , Use of Implementation-Defined Language Features, Conforming Programs
@subsubsection Use of Read-Time Conditionals

Use of @t{#+} and @t{#-} does not automatically disqualify a program
from being conforming.  A program which uses @t{#+} and @t{#-} is 
considered conforming if there is no set of @i{features} in which the
program would not be conforming.  Of course, @i{conforming programs} are
not necessarily working programs.  The following program is conforming:

@example
(defun foo ()
  #+ACME (acme:initialize-something)
  (print 'hello-there))
@end example

However, this program might or might not work, depending on whether the
presence of the feature @t{ACME} really implies that a function named
@t{acme:initialize-something} is present in the environment.  In effect,
using @t{#+} or @t{#-} in a @i{conforming program} means that the variable
@b{*features*}
@IRindex{*features*}

becomes just one more piece of input data to that 
program.  Like any other data coming into a program, the programmer
is responsible for assuring that the program does not make unwarranted
assumptions on the basis of input data.

@c end of including concept-conformance

@node Language Extensions, Language Subsets, Conformance, Introduction (Introduction)
@section Language Extensions

@c including concept-extensions

A language extension is any documented @i{implementation-defined} behavior
of a @i{defined name} in this standard that varies from the
behavior described in this standard, or a documented consequence of a
situation that the standard specifies as undefined, unspecified, or
extendable by the implementation.  For example, if this standard says
that ``the results are unspecified,'' an extension would be to specify
the results.

[Reviewer Note by Barmar: This contradicts previous definitions of conforming code.]
If the correct behavior of a program depends on the results provided
by an extension, only implementations with the same extension will
execute the program correctly.  Note that such a program might be
non-conforming.  Also, if this standard says that ``an implementation
may be extended,'' a conforming, but possibly non-portable, program
can be written using an extension.

An implementation can have extensions, provided they do not alter the
behavior of conforming code and provided they are not explicitly
prohibited by this standard.

The term ``extension'' refers only to extensions available upon
startup.  An implementation is free to allow or prohibit redefinition
of an extension.

The following list contains specific guidance to implementations 
concerning certain types of extensions.
@table @asis

@item @b{Extra return values}  

An implementation must return exactly
the number of return values specified by this standard unless the
standard specifically indicates otherwise.

@item @b{Unsolicited messages}  

No output can be produced by a function other than that specified in
the standard or due to the signaling of @i{conditions}
detected by the function.

Unsolicited output, such as garbage collection notifications and
autoload heralds, should not go directly to the @i{stream}
that is the value of a @i{stream} variable defined in this
standard, but can go indirectly to @i{terminal I/O} by using a
@i{synonym stream} to @b{*terminal-io*}.

Progress reports from such functions as @b{load} and
@b{compile} are considered solicited, and are not covered by
this prohibition.

@item @b{Implementation of macros and special forms}  

@i{Macros} and @i{special operators} defined in this standard
must not be @i{functions}.

@end table

@c end of including concept-extensions

@node Language Subsets, Deprecated Language Features, Language Extensions, Introduction (Introduction)
@section Language Subsets

@c including concept-subsets

The language described in this standard contains no subsets,
though subsets are not forbidden.

For a language to be considered a subset,
it must have the property that any valid @i{program} in that language
has equivalent semantics and will run directly
(with no extralingual pre-processing, and no special compatibility packages)
in any @i{conforming implementation} of the full language.

A language that conforms to this requirement shall be described
as being a ``subset of @r{Common Lisp} as specified by ANSI <<@i{standard number}>>.''

@c end of including concept-subsets

@node Deprecated Language Features, Symbols in the COMMON-LISP Package, Language Subsets, Introduction (Introduction)
@section Deprecated Language Features

@c including concept-deprecated

Deprecated language features are not expected to appear in future @r{Common Lisp}
standards, but are required to be implemented for conformance with this
standard; see @ref{Required Language Features}.

@i{Conforming programs} can use deprecated features;
however, it is considered good programming style to avoid them.
It is permissible for the compiler to produce @i{style warnings} 
about the use of such features at compile time, 
but there should be no such warnings at program execution time.

@menu
* Deprecated Functions::	
* Deprecated Argument Conventions::  
* Deprecated Variables::	
* Deprecated Reader Syntax::	
@end menu

@node Deprecated Functions, Deprecated Argument Conventions, Deprecated Language Features, Deprecated Language Features
@subsection Deprecated Functions

The @i{functions} in Figure 1--2 are deprecated.
@group
@noindent
@w{  assoc-if-not   nsubst-if-not       require            }
@w{  count-if-not   nsubstitute-if-not  set                }
@w{  delete-if-not  position-if-not     subst-if-not       }
@w{  find-if-not    provide             substitute-if-not  }
@w{  gentemp        rassoc-if-not                          }
@w{  member-if-not  remove-if-not                          }

@noindent
@w{            Figure 1--2: Deprecated Functions           }

@end group

@node Deprecated Argument Conventions, Deprecated Variables, Deprecated Functions, Deprecated Language Features
@subsection Deprecated Argument Conventions

The ability to pass a numeric @i{argument} to @b{gensym} has been deprecated.

The @t{:test-not} @i{argument} to the @i{functions} in Figure 1--3 are deprecated.

@group
@noindent
@w{  adjoin             nset-difference    search            }
@w{  assoc              nset-exclusive-or  set-difference    }
@w{  count              nsublis            set-exclusive-or  }
@w{  delete             nsubst             sublis            }
@w{  delete-duplicates  nsubstitute        subsetp           }
@w{  find               nunion             subst             }
@w{  intersection       position           substitute        }
@w{  member             rassoc             tree-equal        }
@w{  mismatch           remove             union             }
@w{  nintersection      remove-duplicates                    }

@noindent
@w{  Figure 1--3: Functions with Deprecated :TEST-NOT Arguments}

@end group

The use of the situation names @b{compile}, @b{load}, and @b{eval}
in @b{eval-when} is deprecated.

@node Deprecated Variables, Deprecated Reader Syntax, Deprecated Argument Conventions, Deprecated Language Features
@subsection Deprecated Variables

The @i{variable} @b{*modules*} is deprecated.

@node Deprecated Reader Syntax,  , Deprecated Variables, Deprecated Language Features
@subsection Deprecated Reader Syntax

The @t{#S} @i{reader macro} forces keyword names into the @t{KEYWORD} @i{package};
see @ref{Sharpsign S}.
This feature is deprecated;
in the future, keyword names will be taken in the package they are read in,
so @i{symbols} that are actually in the @t{KEYWORD} @i{package}
should be used if that is what is desired.

@c end of including concept-deprecated

@node Symbols in the COMMON-LISP Package,  , Deprecated Language Features, Introduction (Introduction)
@section Symbols in the COMMON-LISP Package

@c including concept-cl-symbols

The figures on the next twelve pages contain a complete enumeration
of the 978 @i{external} @i{symbols} in the @t{COMMON-LISP} @i{package}.
@IPindex{common-lisp}

@group
@noindent
@w{  &allow-other-keys            *print-miser-width*          }
@w{  &aux                         *print-pprint-dispatch*      }
@w{  &body                        *print-pretty*               }
@w{  &environment                 *print-radix*                }
@w{  &key                         *print-readably*             }
@w{  &optional                    *print-right-margin*         }
@w{  &rest                        *query-io*                   }
@w{  &whole                       *random-state*               }
@w{  *                            *read-base*                  }
@w{  **                           *read-default-float-format*  }
@w{  ***                          *read-eval*                  }
@w{  *break-on-signals*           *read-suppress*              }
@w{  *compile-file-pathname*      *readtable*                  }
@w{  *compile-file-truename*      *standard-input*             }
@w{  *compile-print*              *standard-output*            }
@w{  *compile-verbose*            *terminal-io*                }
@w{  *debug-io*                   *trace-output*               }
@w{  *debugger-hook*              +                            }
@w{  *default-pathname-defaults*  ++                           }
@w{  *error-output*               +++                          }
@w{  *features*                   -                            }
@w{  *gensym-counter*             /                            }
@w{  *load-pathname*              //                           }
@w{  *load-print*                 ///                          }
@w{  *load-truename*              /=                           }
@w{  *load-verbose*               1+                           }
@w{  *macroexpand-hook*           1-                           }
@w{  *modules*                    <                            }
@w{  *package*                    <=                           }
@w{  *print-array*                =                            }
@w{  *print-base*                 >                            }
@w{  *print-case*                 >=                           }
@w{  *print-circle*               abort                        }
@w{  *print-escape*               abs                          }
@w{  *print-gensym*               acons                        }
@w{  *print-length*               acos                         }
@w{  *print-level*                acosh                        }
@w{  *print-lines*                add-method                   }

@noindent
@w{  Figure 1--4: Symbols in the COMMON-LISP package (part one of twelve).}

@end group

@page

@group
@noindent
@w{  adjoin                      atom          boundp                    }
@w{  adjust-array                base-char     break                     }
@w{  adjustable-array-p          base-string   broadcast-stream          }
@w{  allocate-instance           bignum        broadcast-stream-streams  }
@w{  alpha-char-p                bit           built-in-class            }
@w{  alphanumericp               bit-and       butlast                   }
@w{  and                         bit-andc1     byte                      }
@w{  append                      bit-andc2     byte-position             }
@w{  apply                       bit-eqv       byte-size                 }
@w{  apropos                     bit-ior       caaaar                    }
@w{  apropos-list                bit-nand      caaadr                    }
@w{  aref                        bit-nor       caaar                     }
@w{  arithmetic-error            bit-not       caadar                    }
@w{  arithmetic-error-operands   bit-orc1      caaddr                    }
@w{  arithmetic-error-operation  bit-orc2      caadr                     }
@w{  array                       bit-vector    caar                      }
@w{  array-dimension             bit-vector-p  cadaar                    }
@w{  array-dimension-limit       bit-xor       cadadr                    }
@w{  array-dimensions            block         cadar                     }
@w{  array-displacement          boole         caddar                    }
@w{  array-element-type          boole-1       cadddr                    }
@w{  array-has-fill-pointer-p    boole-2       caddr                     }
@w{  array-in-bounds-p           boole-and     cadr                      }
@w{  array-rank                  boole-andc1   call-arguments-limit      }
@w{  array-rank-limit            boole-andc2   call-method               }
@w{  array-row-major-index       boole-c1      call-next-method          }
@w{  array-total-size            boole-c2      car                       }
@w{  array-total-size-limit      boole-clr     case                      }
@w{  arrayp                      boole-eqv     catch                     }
@w{  ash                         boole-ior     ccase                     }
@w{  asin                        boole-nand    cdaaar                    }
@w{  asinh                       boole-nor     cdaadr                    }
@w{  assert                      boole-orc1    cdaar                     }
@w{  assoc                       boole-orc2    cdadar                    }
@w{  assoc-if                    boole-set     cdaddr                    }
@w{  assoc-if-not                boole-xor     cdadr                     }
@w{  atan                        boolean       cdar                      }
@w{  atanh                       both-case-p   cddaar                    }

@noindent
@w{  Figure 1--5: Symbols in the COMMON-LISP package (part two of twelve).}

@end group

@page

@group
@noindent
@w{  cddadr             clear-input                  copy-tree                  }
@w{  cddar              clear-output                 cos                        }
@w{  cdddar             close                        cosh                       }
@w{  cddddr             clrhash                      count                      }
@w{  cdddr              code-char                    count-if                   }
@w{  cddr               coerce                       count-if-not               }
@w{  cdr                compilation-speed            ctypecase                  }
@w{  ceiling            compile                      debug                      }
@w{  cell-error         compile-file                 decf                       }
@w{  cell-error-name    compile-file-pathname        declaim                    }
@w{  cerror             compiled-function            declaration                }
@w{  change-class       compiled-function-p          declare                    }
@w{  char               compiler-macro               decode-float               }
@w{  char-code          compiler-macro-function      decode-universal-time      }
@w{  char-code-limit    complement                   defclass                   }
@w{  char-downcase      complex                      defconstant                }
@w{  char-equal         complexp                     defgeneric                 }
@w{  char-greaterp      compute-applicable-methods   define-compiler-macro      }
@w{  char-int           compute-restarts             define-condition           }
@w{  char-lessp         concatenate                  define-method-combination  }
@w{  char-name          concatenated-stream          define-modify-macro        }
@w{  char-not-equal     concatenated-stream-streams  define-setf-expander       }
@w{  char-not-greaterp  cond                         define-symbol-macro        }
@w{  char-not-lessp     condition                    defmacro                   }
@w{  char-upcase        conjugate                    defmethod                  }
@w{  char/=             cons                         defpackage                 }
@w{  char<              consp                        defparameter               }
@w{  char<=             constantly                   defsetf                    }
@w{  char=              constantp                    defstruct                  }
@w{  char>              continue                     deftype                    }
@w{  char>=             control-error                defun                      }
@w{  character          copy-alist                   defvar                     }
@w{  characterp         copy-list                    delete                     }
@w{  check-type         copy-pprint-dispatch         delete-duplicates          }
@w{  cis                copy-readtable               delete-file                }
@w{  class              copy-seq                     delete-if                  }
@w{  class-name         copy-structure               delete-if-not              }
@w{  class-of           copy-symbol                  delete-package             }

@noindent
@w{    Figure 1--6: Symbols in the COMMON-LISP package (part three of twelve).  }

@end group

@page

@group
@noindent
@w{  denominator                    eq                   }
@w{  deposit-field                  eql                  }
@w{  describe                       equal                }
@w{  describe-object                equalp               }
@w{  destructuring-bind             error                }
@w{  digit-char                     etypecase            }
@w{  digit-char-p                   eval                 }
@w{  directory                      eval-when            }
@w{  directory-namestring           evenp                }
@w{  disassemble                    every                }
@w{  division-by-zero               exp                  }
@w{  do                             export               }
@w{  do*                            expt                 }
@w{  do-all-symbols                 extended-char        }
@w{  do-external-symbols            fboundp              }
@w{  do-symbols                     fceiling             }
@w{  documentation                  fdefinition          }
@w{  dolist                         ffloor               }
@w{  dotimes                        fifth                }
@w{  double-float                   file-author          }
@w{  double-float-epsilon           file-error           }
@w{  double-float-negative-epsilon  file-error-pathname  }
@w{  dpb                            file-length          }
@w{  dribble                        file-namestring      }
@w{  dynamic-extent                 file-position        }
@w{  ecase                          file-stream          }
@w{  echo-stream                    file-string-length   }
@w{  echo-stream-input-stream       file-write-date      }
@w{  echo-stream-output-stream      fill                 }
@w{  ed                             fill-pointer         }
@w{  eighth                         find                 }
@w{  elt                            find-all-symbols     }
@w{  encode-universal-time          find-class           }
@w{  end-of-file                    find-if              }
@w{  endp                           find-if-not          }
@w{  enough-namestring              find-method          }
@w{  ensure-directories-exist       find-package         }
@w{  ensure-generic-function        find-restart         }

@noindent
@w{  Figure 1--7: Symbols in the COMMON-LISP package (part four of twelve).}

@end group

@page

@group
@noindent
@w{  find-symbol                       get-internal-run-time        }
@w{  finish-output                     get-macro-character          }
@w{  first                             get-output-stream-string     }
@w{  fixnum                            get-properties               }
@w{  flet                              get-setf-expansion           }
@w{  float                             get-universal-time           }
@w{  float-digits                      getf                         }
@w{  float-precision                   gethash                      }
@w{  float-radix                       go                           }
@w{  float-sign                        graphic-char-p               }
@w{  floating-point-inexact            handler-bind                 }
@w{  floating-point-invalid-operation  handler-case                 }
@w{  floating-point-overflow           hash-table                   }
@w{  floating-point-underflow          hash-table-count             }
@w{  floatp                            hash-table-p                 }
@w{  floor                             hash-table-rehash-size       }
@w{  fmakunbound                       hash-table-rehash-threshold  }
@w{  force-output                      hash-table-size              }
@w{  format                            hash-table-test              }
@w{  formatter                         host-namestring              }
@w{  fourth                            identity                     }
@w{  fresh-line                        if                           }
@w{  fround                            ignorable                    }
@w{  ftruncate                         ignore                       }
@w{  ftype                             ignore-errors                }
@w{  funcall                           imagpart                     }
@w{  function                          import                       }
@w{  function-keywords                 in-package                   }
@w{  function-lambda-expression        incf                         }
@w{  functionp                         initialize-instance          }
@w{  gcd                               inline                       }
@w{  generic-function                  input-stream-p               }
@w{  gensym                            inspect                      }
@w{  gentemp                           integer                      }
@w{  get                               integer-decode-float         }
@w{  get-decoded-time                  integer-length               }
@w{  get-dispatch-macro-character      integerp                     }
@w{  get-internal-real-time            interactive-stream-p         }

@noindent
@w{  Figure 1--8: Symbols in the COMMON-LISP package (part five of twelve).}

@end group

@page

@group
@noindent
@w{  intern                                  lisp-implementation-type            }
@w{  internal-time-units-per-second          lisp-implementation-version         }
@w{  intersection                            list                                }
@w{  invalid-method-error                    list*                               }
@w{  invoke-debugger                         list-all-packages                   }
@w{  invoke-restart                          list-length                         }
@w{  invoke-restart-interactively            listen                              }
@w{  isqrt                                   listp                               }
@w{  keyword                                 load                                }
@w{  keywordp                                load-logical-pathname-translations  }
@w{  labels                                  load-time-value                     }
@w{  lambda                                  locally                             }
@w{  lambda-list-keywords                    log                                 }
@w{  lambda-parameters-limit                 logand                              }
@w{  last                                    logandc1                            }
@w{  lcm                                     logandc2                            }
@w{  ldb                                     logbitp                             }
@w{  ldb-test                                logcount                            }
@w{  ldiff                                   logeqv                              }
@w{  least-negative-double-float             logical-pathname                    }
@w{  least-negative-long-float               logical-pathname-translations       }
@w{  least-negative-normalized-double-float  logior                              }
@w{  least-negative-normalized-long-float    lognand                             }
@w{  least-negative-normalized-short-float   lognor                              }
@w{  least-negative-normalized-single-float  lognot                              }
@w{  least-negative-short-float              logorc1                             }
@w{  least-negative-single-float             logorc2                             }
@w{  least-positive-double-float             logtest                             }
@w{  least-positive-long-float               logxor                              }
@w{  least-positive-normalized-double-float  long-float                          }
@w{  least-positive-normalized-long-float    long-float-epsilon                  }
@w{  least-positive-normalized-short-float   long-float-negative-epsilon         }
@w{  least-positive-normalized-single-float  long-site-name                      }
@w{  least-positive-short-float              loop                                }
@w{  least-positive-single-float             loop-finish                         }
@w{  length                                  lower-case-p                        }
@w{  let                                     machine-instance                    }
@w{  let*                                    machine-type                        }

@noindent
@w{     Figure 1--9: Symbols in the COMMON-LISP package (part six of twelve).    }

@end group

@page

@group
@noindent
@w{  machine-version                mask-field                  }
@w{  macro-function                 max                         }
@w{  macroexpand                    member                      }
@w{  macroexpand-1                  member-if                   }
@w{  macrolet                       member-if-not               }
@w{  make-array                     merge                       }
@w{  make-broadcast-stream          merge-pathnames             }
@w{  make-concatenated-stream       method                      }
@w{  make-condition                 method-combination          }
@w{  make-dispatch-macro-character  method-combination-error    }
@w{  make-echo-stream               method-qualifiers           }
@w{  make-hash-table                min                         }
@w{  make-instance                  minusp                      }
@w{  make-instances-obsolete        mismatch                    }
@w{  make-list                      mod                         }
@w{  make-load-form                 most-negative-double-float  }
@w{  make-load-form-saving-slots    most-negative-fixnum        }
@w{  make-method                    most-negative-long-float    }
@w{  make-package                   most-negative-short-float   }
@w{  make-pathname                  most-negative-single-float  }
@w{  make-random-state              most-positive-double-float  }
@w{  make-sequence                  most-positive-fixnum        }
@w{  make-string                    most-positive-long-float    }
@w{  make-string-input-stream       most-positive-short-float   }
@w{  make-string-output-stream      most-positive-single-float  }
@w{  make-symbol                    muffle-warning              }
@w{  make-synonym-stream            multiple-value-bind         }
@w{  make-two-way-stream            multiple-value-call         }
@w{  makunbound                     multiple-value-list         }
@w{  map                            multiple-value-prog1        }
@w{  map-into                       multiple-value-setq         }
@w{  mapc                           multiple-values-limit       }
@w{  mapcan                         name-char                   }
@w{  mapcar                         namestring                  }
@w{  mapcon                         nbutlast                    }
@w{  maphash                        nconc                       }
@w{  mapl                           next-method-p               }
@w{  maplist                        nil                         }

@noindent
@w{  Figure 1--10: Symbols in the COMMON-LISP package (part seven of twelve).}

@end group

@page

@group
@noindent
@w{  nintersection         package-error                  }
@w{  ninth                 package-error-package          }
@w{  no-applicable-method  package-name                   }
@w{  no-next-method        package-nicknames              }
@w{  not                   package-shadowing-symbols      }
@w{  notany                package-use-list               }
@w{  notevery              package-used-by-list           }
@w{  notinline             packagep                       }
@w{  nreconc               pairlis                        }
@w{  nreverse              parse-error                    }
@w{  nset-difference       parse-integer                  }
@w{  nset-exclusive-or     parse-namestring               }
@w{  nstring-capitalize    pathname                       }
@w{  nstring-downcase      pathname-device                }
@w{  nstring-upcase        pathname-directory             }
@w{  nsublis               pathname-host                  }
@w{  nsubst                pathname-match-p               }
@w{  nsubst-if             pathname-name                  }
@w{  nsubst-if-not         pathname-type                  }
@w{  nsubstitute           pathname-version               }
@w{  nsubstitute-if        pathnamep                      }
@w{  nsubstitute-if-not    peek-char                      }
@w{  nth                   phase                          }
@w{  nth-value             pi                             }
@w{  nthcdr                plusp                          }
@w{  null                  pop                            }
@w{  number                position                       }
@w{  numberp               position-if                    }
@w{  numerator             position-if-not                }
@w{  nunion                pprint                         }
@w{  oddp                  pprint-dispatch                }
@w{  open                  pprint-exit-if-list-exhausted  }
@w{  open-stream-p         pprint-fill                    }
@w{  optimize              pprint-indent                  }
@w{  or                    pprint-linear                  }
@w{  otherwise             pprint-logical-block           }
@w{  output-stream-p       pprint-newline                 }
@w{  package               pprint-pop                     }

@noindent
@w{  Figure 1--11: Symbols in the COMMON-LISP package (part eight of twelve).}

@end group

@page

@group
@noindent
@w{  pprint-tab                 read-char                   }
@w{  pprint-tabular             read-char-no-hang           }
@w{  prin1                      read-delimited-list         }
@w{  prin1-to-string            read-from-string            }
@w{  princ                      read-line                   }
@w{  princ-to-string            read-preserving-whitespace  }
@w{  print                      read-sequence               }
@w{  print-not-readable         reader-error                }
@w{  print-not-readable-object  readtable                   }
@w{  print-object               readtable-case              }
@w{  print-unreadable-object    readtablep                  }
@w{  probe-file                 real                        }
@w{  proclaim                   realp                       }
@w{  prog                       realpart                    }
@w{  prog*                      reduce                      }
@w{  prog1                      reinitialize-instance       }
@w{  prog2                      rem                         }
@w{  progn                      remf                        }
@w{  program-error              remhash                     }
@w{  progv                      remove                      }
@w{  provide                    remove-duplicates           }
@w{  psetf                      remove-if                   }
@w{  psetq                      remove-if-not               }
@w{  push                       remove-method               }
@w{  pushnew                    remprop                     }
@w{  quote                      rename-file                 }
@w{  random                     rename-package              }
@w{  random-state               replace                     }
@w{  random-state-p             require                     }
@w{  rassoc                     rest                        }
@w{  rassoc-if                  restart                     }
@w{  rassoc-if-not              restart-bind                }
@w{  ratio                      restart-case                }
@w{  rational                   restart-name                }
@w{  rationalize                return                      }
@w{  rationalp                  return-from                 }
@w{  read                       revappend                   }
@w{  read-byte                  reverse                     }

@noindent
@w{  Figure 1--12: Symbols in the COMMON-LISP package (part nine of twelve).}

@end group

@page

@group
@noindent
@w{  room                          simple-bit-vector                  }
@w{  rotatef                       simple-bit-vector-p                }
@w{  round                         simple-condition                   }
@w{  row-major-aref                simple-condition-format-arguments  }
@w{  rplaca                        simple-condition-format-control    }
@w{  rplacd                        simple-error                       }
@w{  safety                        simple-string                      }
@w{  satisfies                     simple-string-p                    }
@w{  sbit                          simple-type-error                  }
@w{  scale-float                   simple-vector                      }
@w{  schar                         simple-vector-p                    }
@w{  search                        simple-warning                     }
@w{  second                        sin                                }
@w{  sequence                      single-float                       }
@w{  serious-condition             single-float-epsilon               }
@w{  set                           single-float-negative-epsilon      }
@w{  set-difference                sinh                               }
@w{  set-dispatch-macro-character  sixth                              }
@w{  set-exclusive-or              sleep                              }
@w{  set-macro-character           slot-boundp                        }
@w{  set-pprint-dispatch           slot-exists-p                      }
@w{  set-syntax-from-char          slot-makunbound                    }
@w{  setf                          slot-missing                       }
@w{  setq                          slot-unbound                       }
@w{  seventh                       slot-value                         }
@w{  shadow                        software-type                      }
@w{  shadowing-import              software-version                   }
@w{  shared-initialize             some                               }
@w{  shiftf                        sort                               }
@w{  short-float                   space                              }
@w{  short-float-epsilon           special                            }
@w{  short-float-negative-epsilon  special-operator-p                 }
@w{  short-site-name               speed                              }
@w{  signal                        sqrt                               }
@w{  signed-byte                   stable-sort                        }
@w{  signum                        standard                           }
@w{  simple-array                  standard-char                      }
@w{  simple-base-string            standard-char-p                    }

@noindent
@w{  Figure 1--13: Symbols in the COMMON-LISP package (part ten of twelve).}

@end group

@page

@group
@noindent
@w{  standard-class             sublis                      }
@w{  standard-generic-function  subseq                      }
@w{  standard-method            subsetp                     }
@w{  standard-object            subst                       }
@w{  step                       subst-if                    }
@w{  storage-condition          subst-if-not                }
@w{  store-value                substitute                  }
@w{  stream                     substitute-if               }
@w{  stream-element-type        substitute-if-not           }
@w{  stream-error               subtypep                    }
@w{  stream-error-stream        svref                       }
@w{  stream-external-format     sxhash                      }
@w{  streamp                    symbol                      }
@w{  string                     symbol-function             }
@w{  string-capitalize          symbol-macrolet             }
@w{  string-downcase            symbol-name                 }
@w{  string-equal               symbol-package              }
@w{  string-greaterp            symbol-plist                }
@w{  string-left-trim           symbol-value                }
@w{  string-lessp               symbolp                     }
@w{  string-not-equal           synonym-stream              }
@w{  string-not-greaterp        synonym-stream-symbol       }
@w{  string-not-lessp           t                           }
@w{  string-right-trim          tagbody                     }
@w{  string-stream              tailp                       }
@w{  string-trim                tan                         }
@w{  string-upcase              tanh                        }
@w{  string/=                   tenth                       }
@w{  string<                    terpri                      }
@w{  string<=                   the                         }
@w{  string=                    third                       }
@w{  string>                    throw                       }
@w{  string>=                   time                        }
@w{  stringp                    trace                       }
@w{  structure                  translate-logical-pathname  }
@w{  structure-class            translate-pathname          }
@w{  structure-object           tree-equal                  }
@w{  style-warning              truename                    }

@noindent
@w{  Figure 1--14: Symbols in the COMMON-LISP package (part eleven of twelve).}

@end group

@page

@group
@noindent
@w{  truncate                             values-list               }
@w{  two-way-stream                       variable                  }
@w{  two-way-stream-input-stream          vector                    }
@w{  two-way-stream-output-stream         vector-pop                }
@w{  type                                 vector-push               }
@w{  type-error                           vector-push-extend        }
@w{  type-error-datum                     vectorp                   }
@w{  type-error-expected-type             warn                      }
@w{  type-of                              warning                   }
@w{  typecase                             when                      }
@w{  typep                                wild-pathname-p           }
@w{  unbound-slot                         with-accessors            }
@w{  unbound-slot-instance                with-compilation-unit     }
@w{  unbound-variable                     with-condition-restarts   }
@w{  undefined-function                   with-hash-table-iterator  }
@w{  unexport                             with-input-from-string    }
@w{  unintern                             with-open-file            }
@w{  union                                with-open-stream          }
@w{  unless                               with-output-to-string     }
@w{  unread-char                          with-package-iterator     }
@w{  unsigned-byte                        with-simple-restart       }
@w{  untrace                              with-slots                }
@w{  unuse-package                        with-standard-io-syntax   }
@w{  unwind-protect                       write                     }
@w{  update-instance-for-different-class  write-byte                }
@w{  update-instance-for-redefined-class  write-char                }
@w{  upgraded-array-element-type          write-line                }
@w{  upgraded-complex-part-type           write-sequence            }
@w{  upper-case-p                         write-string              }
@w{  use-package                          write-to-string           }
@w{  use-value                            y-or-n-p                  }
@w{  user-homedir-pathname                yes-or-no-p               }
@w{  values                               zerop                     }

@noindent
@w{  Figure 1--15: Symbols in the COMMON-LISP package (part twelve of twelve).}

@end group

@c end of including concept-cl-symbols

@c %**end of chapter

