diff options
| -rw-r--r-- | Doc/copyright.tex | 4 | ||||
| -rw-r--r-- | Doc/lib.tex | 3 | ||||
| -rw-r--r-- | Doc/lib/lib.tex | 3 | ||||
| -rw-r--r-- | Doc/lib/libmath.tex | 4 | ||||
| -rw-r--r-- | Doc/lib/libmd5.tex | 14 | ||||
| -rw-r--r-- | Doc/lib/libposix.tex | 6 | ||||
| -rw-r--r-- | Doc/lib/libposixfile.tex | 2 | ||||
| -rw-r--r-- | Doc/lib/libsocket.tex | 11 | ||||
| -rw-r--r-- | Doc/lib/libtypes.tex | 9 | ||||
| -rw-r--r-- | Doc/libmath.tex | 4 | ||||
| -rw-r--r-- | Doc/libmd5.tex | 14 | ||||
| -rw-r--r-- | Doc/libposix.tex | 6 | ||||
| -rw-r--r-- | Doc/libposixfile.tex | 2 | ||||
| -rw-r--r-- | Doc/libsocket.tex | 11 | ||||
| -rw-r--r-- | Doc/libtypes.tex | 9 | ||||
| -rw-r--r-- | Doc/ref/ref3.tex | 12 | ||||
| -rw-r--r-- | Doc/ref/ref4.tex | 6 | ||||
| -rw-r--r-- | Doc/ref/ref5.tex | 10 | ||||
| -rw-r--r-- | Doc/ref/ref6.tex | 4 | ||||
| -rw-r--r-- | Doc/ref/ref7.tex | 2 | ||||
| -rw-r--r-- | Doc/ref3.tex | 12 | ||||
| -rw-r--r-- | Doc/ref4.tex | 6 | ||||
| -rw-r--r-- | Doc/ref5.tex | 10 | ||||
| -rw-r--r-- | Doc/ref6.tex | 4 | ||||
| -rw-r--r-- | Doc/ref7.tex | 2 | ||||
| -rw-r--r-- | Doc/texinputs/copyright.tex | 4 |
26 files changed, 134 insertions, 40 deletions
diff --git a/Doc/copyright.tex b/Doc/copyright.tex index f445c40afa..d870d3cab2 100644 --- a/Doc/copyright.tex +++ b/Doc/copyright.tex @@ -1,5 +1,5 @@ -Copyright 1991, 1992, 1993, 1994 by Stichting Mathematisch Centrum, -Amsterdam, The Netherlands. +Copyright 1991-1995 by Stichting Mathematisch Centrum, Amsterdam, +The Netherlands. \begin{center} All Rights Reserved diff --git a/Doc/lib.tex b/Doc/lib.tex index 900cfacec7..d3901b222d 100644 --- a/Doc/lib.tex +++ b/Doc/lib.tex @@ -50,6 +50,7 @@ language. \input{libmods} % Built-in modules \input{libsys} \input{libbltin} % really __builtin__ +\input{libimp} \input{libmain} % really __main__ \input{libarray} \input{libmath} @@ -73,7 +74,7 @@ language. \input{libgdbm} \input{libgrp} \input{libposix} -\input{libposixfile} % XXX this uses lineii which partparse.py doesn't know +\input{libposixfile} \input{libppath} % really posixpath \input{libpwd} \input{libselect} diff --git a/Doc/lib/lib.tex b/Doc/lib/lib.tex index 900cfacec7..d3901b222d 100644 --- a/Doc/lib/lib.tex +++ b/Doc/lib/lib.tex @@ -50,6 +50,7 @@ language. \input{libmods} % Built-in modules \input{libsys} \input{libbltin} % really __builtin__ +\input{libimp} \input{libmain} % really __main__ \input{libarray} \input{libmath} @@ -73,7 +74,7 @@ language. \input{libgdbm} \input{libgrp} \input{libposix} -\input{libposixfile} % XXX this uses lineii which partparse.py doesn't know +\input{libposixfile} \input{libppath} % really posixpath \input{libpwd} \input{libselect} diff --git a/Doc/lib/libmath.tex b/Doc/lib/libmath.tex index c26e849957..6c6a90f9c0 100644 --- a/Doc/lib/libmath.tex +++ b/Doc/lib/libmath.tex @@ -44,6 +44,7 @@ They are: \code{floor(\varvars{x})}, \code{fmod(\varvars{x\, y})}, \code{frexp(\varvars{x})}, +\code{hypot(\varvars{x\, y})}, \code{ldexp(\varvars{x\, y})}, \code{log(\varvars{x})}, \code{log10(\varvars{x})}, @@ -61,6 +62,9 @@ pattern than their C equivalents: they take a single argument and return a pair of values, rather than returning their second return value through an `output parameter' (there is no such thing in Python). +The \code{hypot} function, which is not standard C, is not available +on all platforms. + The module also defines two mathematical constants: \iftexi \begin{datadesc}{pi} diff --git a/Doc/lib/libmd5.tex b/Doc/lib/libmd5.tex index edaa727248..3e228201a0 100644 --- a/Doc/lib/libmd5.tex +++ b/Doc/lib/libmd5.tex @@ -15,8 +15,8 @@ example will be helpful: to obtain the digest of the string \code{'abc'}, use \ldots \bcode\begin{verbatim} ->>> from md5 import md5 ->>> m = md5() +>>> import md5 +>>> m = md5.new() >>> m.update('abc') >>> m.digest() '\220\001P\230<\322O\260\326\226?}(\341\177r' @@ -25,16 +25,22 @@ to obtain the digest of the string \code{'abc'}, use \ldots More condensed: \bcode\begin{verbatim} ->>> md5('abc').digest() +>>> md5.new('abc').digest() '\220\001P\230<\322O\260\326\226?}(\341\177r' \end{verbatim}\ecode \renewcommand{\indexsubitem}{(in module md5)} -\begin{funcdesc}{md5}{\optional{arg}} + +\begin{funcdesc}{new}{\optional{arg}} Create a new md5-object. If \var{arg} is present, an initial \code{update} method is called with \var{arg} as argument. \end{funcdesc} +\begin{funcdesc}{md5}{\optional{arg}} +For backward compatibility reasons, this is an alternative name for the +\code{new} function. +\end{funcdesc} + An md5-object has the following methods: \renewcommand{\indexsubitem}{(md5 method)} diff --git a/Doc/lib/libposix.tex b/Doc/lib/libposix.tex index c22f1e0657..987f746e8b 100644 --- a/Doc/lib/libposix.tex +++ b/Doc/lib/libposix.tex @@ -50,6 +50,12 @@ Change the current working directory to \var{path}. Change the mode of \var{path} to the numeric \var{mode}. \end{funcdesc} +\begin{funcdesc}{chown}{path\, uid, gid} +Change the owner and group id of \var{path} to the numeric \var{uid} +and \var{gid}. +(Not on MS-DOS.) +\end{funcdesc} + \begin{funcdesc}{close}{fd} Close file descriptor \var{fd}. \end{funcdesc} diff --git a/Doc/lib/libposixfile.tex b/Doc/lib/libposixfile.tex index 346f5769f4..050ba5a94a 100644 --- a/Doc/lib/libposixfile.tex +++ b/Doc/lib/libposixfile.tex @@ -38,7 +38,7 @@ The posixfile module defines the following functions: builtin function. \end{funcdesc} -\begin{funcdesc}{openfile}{fileobject} +\begin{funcdesc}{fileopen}{fileobject} Create a new posixfile object with the given standard file object. The resulting object has the same filename and mode as the original file object. diff --git a/Doc/lib/libsocket.tex b/Doc/lib/libsocket.tex index 60b9d15b88..1026ef1858 100644 --- a/Doc/lib/libsocket.tex +++ b/Doc/lib/libsocket.tex @@ -79,7 +79,16 @@ is an IP address itself it is returned unchanged. Return a string containing the hostname of the machine where the Python interpreter is currently executing. If you want to know the current machine's IP address, use -\code{socket.gethostbyname( socket.gethostname() )} instead. +\code{socket.gethostbyname(socket.gethostname())} instead. +\end{funcdesc} + +\begin{funcdesc}{gethostbyaddr}{ip_address} +Return a triple \code{(hostname, aliaslist, ipaddrlist)} where +\code{hostname} is the primary host name responding to the given +\var{ip_address}, \code{aliaslist} is a (possibly empty) list of +alternative host names for the same address, and \code{ipaddrlist} is +a list of IP addresses for the same interface on the same +host (most likely containing only a single address). \end{funcdesc} \begin{funcdesc}{getservbyname}{servicename\, protocolname} diff --git a/Doc/lib/libtypes.tex b/Doc/lib/libtypes.tex index b5dadaf17a..1d5beb4303 100644 --- a/Doc/lib/libtypes.tex +++ b/Doc/lib/libtypes.tex @@ -580,7 +580,14 @@ Files have the following methods: \begin{funcdesc}{readline}{} Read one entire line from the file. A trailing newline character is - kept in the string (but may be absent when a file ends with an + kept in the string% +\footnote{The advantage of leaving the newline on is that an empty string + can be returned to mean \EOF{} without being ambiguous. Another + advantage is that (in cases where it might matter, e.g. if you + want to make an exact copy of a file while scanning its lines) + you can tell whether the last line of a file ended in a newline + or not (yes this happens!).} + (but may be absent when a file ends with an incomplete line). An empty string is returned when \EOF{} is hit immediately. Note: unlike \code{stdio}'s \code{fgets()}, the returned string contains null characters (\code{'\e 0'}) if they occurred in the diff --git a/Doc/libmath.tex b/Doc/libmath.tex index c26e849957..6c6a90f9c0 100644 --- a/Doc/libmath.tex +++ b/Doc/libmath.tex @@ -44,6 +44,7 @@ They are: \code{floor(\varvars{x})}, \code{fmod(\varvars{x\, y})}, \code{frexp(\varvars{x})}, +\code{hypot(\varvars{x\, y})}, \code{ldexp(\varvars{x\, y})}, \code{log(\varvars{x})}, \code{log10(\varvars{x})}, @@ -61,6 +62,9 @@ pattern than their C equivalents: they take a single argument and return a pair of values, rather than returning their second return value through an `output parameter' (there is no such thing in Python). +The \code{hypot} function, which is not standard C, is not available +on all platforms. + The module also defines two mathematical constants: \iftexi \begin{datadesc}{pi} diff --git a/Doc/libmd5.tex b/Doc/libmd5.tex index edaa727248..3e228201a0 100644 --- a/Doc/libmd5.tex +++ b/Doc/libmd5.tex @@ -15,8 +15,8 @@ example will be helpful: to obtain the digest of the string \code{'abc'}, use \ldots \bcode\begin{verbatim} ->>> from md5 import md5 ->>> m = md5() +>>> import md5 +>>> m = md5.new() >>> m.update('abc') >>> m.digest() '\220\001P\230<\322O\260\326\226?}(\341\177r' @@ -25,16 +25,22 @@ to obtain the digest of the string \code{'abc'}, use \ldots More condensed: \bcode\begin{verbatim} ->>> md5('abc').digest() +>>> md5.new('abc').digest() '\220\001P\230<\322O\260\326\226?}(\341\177r' \end{verbatim}\ecode \renewcommand{\indexsubitem}{(in module md5)} -\begin{funcdesc}{md5}{\optional{arg}} + +\begin{funcdesc}{new}{\optional{arg}} Create a new md5-object. If \var{arg} is present, an initial \code{update} method is called with \var{arg} as argument. \end{funcdesc} +\begin{funcdesc}{md5}{\optional{arg}} +For backward compatibility reasons, this is an alternative name for the +\code{new} function. +\end{funcdesc} + An md5-object has the following methods: \renewcommand{\indexsubitem}{(md5 method)} diff --git a/Doc/libposix.tex b/Doc/libposix.tex index c22f1e0657..987f746e8b 100644 --- a/Doc/libposix.tex +++ b/Doc/libposix.tex @@ -50,6 +50,12 @@ Change the current working directory to \var{path}. Change the mode of \var{path} to the numeric \var{mode}. \end{funcdesc} +\begin{funcdesc}{chown}{path\, uid, gid} +Change the owner and group id of \var{path} to the numeric \var{uid} +and \var{gid}. +(Not on MS-DOS.) +\end{funcdesc} + \begin{funcdesc}{close}{fd} Close file descriptor \var{fd}. \end{funcdesc} diff --git a/Doc/libposixfile.tex b/Doc/libposixfile.tex index 346f5769f4..050ba5a94a 100644 --- a/Doc/libposixfile.tex +++ b/Doc/libposixfile.tex @@ -38,7 +38,7 @@ The posixfile module defines the following functions: builtin function. \end{funcdesc} -\begin{funcdesc}{openfile}{fileobject} +\begin{funcdesc}{fileopen}{fileobject} Create a new posixfile object with the given standard file object. The resulting object has the same filename and mode as the original file object. diff --git a/Doc/libsocket.tex b/Doc/libsocket.tex index 60b9d15b88..1026ef1858 100644 --- a/Doc/libsocket.tex +++ b/Doc/libsocket.tex @@ -79,7 +79,16 @@ is an IP address itself it is returned unchanged. Return a string containing the hostname of the machine where the Python interpreter is currently executing. If you want to know the current machine's IP address, use -\code{socket.gethostbyname( socket.gethostname() )} instead. +\code{socket.gethostbyname(socket.gethostname())} instead. +\end{funcdesc} + +\begin{funcdesc}{gethostbyaddr}{ip_address} +Return a triple \code{(hostname, aliaslist, ipaddrlist)} where +\code{hostname} is the primary host name responding to the given +\var{ip_address}, \code{aliaslist} is a (possibly empty) list of +alternative host names for the same address, and \code{ipaddrlist} is +a list of IP addresses for the same interface on the same +host (most likely containing only a single address). \end{funcdesc} \begin{funcdesc}{getservbyname}{servicename\, protocolname} diff --git a/Doc/libtypes.tex b/Doc/libtypes.tex index b5dadaf17a..1d5beb4303 100644 --- a/Doc/libtypes.tex +++ b/Doc/libtypes.tex @@ -580,7 +580,14 @@ Files have the following methods: \begin{funcdesc}{readline}{} Read one entire line from the file. A trailing newline character is - kept in the string (but may be absent when a file ends with an + kept in the string% +\footnote{The advantage of leaving the newline on is that an empty string + can be returned to mean \EOF{} without being ambiguous. Another + advantage is that (in cases where it might matter, e.g. if you + want to make an exact copy of a file while scanning its lines) + you can tell whether the last line of a file ended in a newline + or not (yes this happens!).} + (but may be absent when a file ends with an incomplete line). An empty string is returned when \EOF{} is hit immediately. Note: unlike \code{stdio}'s \code{fgets()}, the returned string contains null characters (\code{'\e 0'}) if they occurred in the diff --git a/Doc/ref/ref3.tex b/Doc/ref/ref3.tex index 8d327e0e00..67848bb8b4 100644 --- a/Doc/ref/ref3.tex +++ b/Doc/ref/ref3.tex @@ -470,7 +470,7 @@ A file object represents an open file. (It is a wrapper around a C \verb@open()@ built-in function, and also by \verb@posix.popen()@ and the \verb@makefile@ method of socket objects. \verb@sys.stdin@, \verb@sys.stdout@ and \verb@sys.stderr@ are file objects corresponding -the the interpreter's standard input, output and error streams. +to the interpreter's standard input, output and error streams. See the Python Library Reference for methods of file objects and other details. \obindex{file} @@ -498,7 +498,7 @@ but they are mentioned here for completeness. Code objects represent executable code. The difference between a code object and a function object is that the function object contains an explicit reference to the function's context (the module in which it -was defined) which a code object contains no context. There is no way +was defined) while a code object contains no context. There is no way to execute a bare code object. \obindex{code} @@ -622,8 +622,12 @@ former decrements the reference count for \code{x} by one, but \code{x,__del__} is only called when its reference count reaches zero. \item[\tt __repr__(self)] -Called by the \verb@repr()@ built-in function and by conversions -(reverse quotes) to compute the string representation of an object. +Called by the \verb@repr()@ built-in function and by string conversions +(reverse or backward quotes) to compute the string representation of an object. +\indexii{string}{conversion} +\indexii{reverse}{quotes} +\indexii{backward}{quotes} +\index{back-quotes} \item[\tt __str__(self)] Called by the \verb@str()@ built-in function and by the \verb@print@ diff --git a/Doc/ref/ref4.tex b/Doc/ref/ref4.tex index c4c4abc243..0198117c41 100644 --- a/Doc/ref/ref4.tex +++ b/Doc/ref/ref4.tex @@ -72,9 +72,9 @@ When a global name is not found in the global name space, it is searched in the list of ``built-in'' names (which is actually the global name space of the module \verb@__builtin__@). When a name is not found at all, the \verb@NameError@ exception is raised.% -\footnote{If the code block contains \verb@exec@ statements or the -construct \verb@from ... import *@, the semantics of names not -explicitly mentioned in a \verb@global@ statement change subtly: name +\footnote{If the code block contains {\tt exec} statements or the +construct {\tt from \ldots import *}, the semantics of names not +explicitly mentioned in a {\tt global} statement change subtly: name lookup first searches the local name space, then the global one, then the built-in one.} diff --git a/Doc/ref/ref5.tex b/Doc/ref/ref5.tex index a4a7b530c2..af385aac8e 100644 --- a/Doc/ref/ref5.tex +++ b/Doc/ref/ref5.tex @@ -187,6 +187,9 @@ value prevails. \subsection{String conversions} \indexii{string}{conversion} +\indexii{reverse}{quotes} +\indexii{backward}{quotes} +\index{back-quotes} A string conversion is a condition list enclosed in reverse (or backward) quotes: @@ -214,6 +217,13 @@ dictionaries that contain a reference to themselves, directly or indirectly.) \obindex{recursive} +The built-in function \verb@repr()@ performs exactly the same +conversion in its argument as enclosing it it reverse quotes does. +The built-in function \verb@str()@ performs a similar but more +user-friendly conversion. +\bifuncindex{repr} +\bifuncindex{str} + \section{Primaries} \label{primaries} \index{primary} diff --git a/Doc/ref/ref6.tex b/Doc/ref/ref6.tex index 53e6c403de..70e1a68a63 100644 --- a/Doc/ref/ref6.tex +++ b/Doc/ref/ref6.tex @@ -166,7 +166,7 @@ sequence cannot add new items to a list). If the primary is a mapping (dictionary) object, the subscript must have a type compatible with the mapping's key type, and the mapping is -then asked to to create a key/datum pair which maps the subscript to +then asked to create a key/datum pair which maps the subscript to the assigned object. This can either replace an existing key/value pair with the same key value, or insert a new key/value pair (if no key with the same value existed). @@ -369,7 +369,7 @@ continue_stmt: "continue" \verb@continue@ may only occur syntactically nested in a \verb@for@ or \verb@while@ loop, but not nested in a function or class definition or \verb@try@ statement within that loop.\footnote{Except that it may -currently occur within an \verb@except@ clause.} +currently occur within an {\tt except} clause.} \stindex{for} \stindex{while} \indexii{loop}{statement} diff --git a/Doc/ref/ref7.tex b/Doc/ref/ref7.tex index b8babfb910..f099ae5543 100644 --- a/Doc/ref/ref7.tex +++ b/Doc/ref/ref7.tex @@ -299,7 +299,7 @@ default value is substituted. If a parameter has a default value, all following parameters must also have a default value --- this is a syntactic restriction that is not expressed by the grammar.% \footnote{Currently this is not checked; instead, -\verb@def f(a=1,b)@ is interpreted as \verb@def f(a=1,b=None)@.} +{\tt def f(a=1,b)} is interpreted as {\tt def f(a=1,b=None)}.} \indexiii{default}{parameter}{value} Function call semantics are described in section \ref{calls}. When a diff --git a/Doc/ref3.tex b/Doc/ref3.tex index 8d327e0e00..67848bb8b4 100644 --- a/Doc/ref3.tex +++ b/Doc/ref3.tex @@ -470,7 +470,7 @@ A file object represents an open file. (It is a wrapper around a C \verb@open()@ built-in function, and also by \verb@posix.popen()@ and the \verb@makefile@ method of socket objects. \verb@sys.stdin@, \verb@sys.stdout@ and \verb@sys.stderr@ are file objects corresponding -the the interpreter's standard input, output and error streams. +to the interpreter's standard input, output and error streams. See the Python Library Reference for methods of file objects and other details. \obindex{file} @@ -498,7 +498,7 @@ but they are mentioned here for completeness. Code objects represent executable code. The difference between a code object and a function object is that the function object contains an explicit reference to the function's context (the module in which it -was defined) which a code object contains no context. There is no way +was defined) while a code object contains no context. There is no way to execute a bare code object. \obindex{code} @@ -622,8 +622,12 @@ former decrements the reference count for \code{x} by one, but \code{x,__del__} is only called when its reference count reaches zero. \item[\tt __repr__(self)] -Called by the \verb@repr()@ built-in function and by conversions -(reverse quotes) to compute the string representation of an object. +Called by the \verb@repr()@ built-in function and by string conversions +(reverse or backward quotes) to compute the string representation of an object. +\indexii{string}{conversion} +\indexii{reverse}{quotes} +\indexii{backward}{quotes} +\index{back-quotes} \item[\tt __str__(self)] Called by the \verb@str()@ built-in function and by the \verb@print@ diff --git a/Doc/ref4.tex b/Doc/ref4.tex index c4c4abc243..0198117c41 100644 --- a/Doc/ref4.tex +++ b/Doc/ref4.tex @@ -72,9 +72,9 @@ When a global name is not found in the global name space, it is searched in the list of ``built-in'' names (which is actually the global name space of the module \verb@__builtin__@). When a name is not found at all, the \verb@NameError@ exception is raised.% -\footnote{If the code block contains \verb@exec@ statements or the -construct \verb@from ... import *@, the semantics of names not -explicitly mentioned in a \verb@global@ statement change subtly: name +\footnote{If the code block contains {\tt exec} statements or the +construct {\tt from \ldots import *}, the semantics of names not +explicitly mentioned in a {\tt global} statement change subtly: name lookup first searches the local name space, then the global one, then the built-in one.} diff --git a/Doc/ref5.tex b/Doc/ref5.tex index a4a7b530c2..af385aac8e 100644 --- a/Doc/ref5.tex +++ b/Doc/ref5.tex @@ -187,6 +187,9 @@ value prevails. \subsection{String conversions} \indexii{string}{conversion} +\indexii{reverse}{quotes} +\indexii{backward}{quotes} +\index{back-quotes} A string conversion is a condition list enclosed in reverse (or backward) quotes: @@ -214,6 +217,13 @@ dictionaries that contain a reference to themselves, directly or indirectly.) \obindex{recursive} +The built-in function \verb@repr()@ performs exactly the same +conversion in its argument as enclosing it it reverse quotes does. +The built-in function \verb@str()@ performs a similar but more +user-friendly conversion. +\bifuncindex{repr} +\bifuncindex{str} + \section{Primaries} \label{primaries} \index{primary} diff --git a/Doc/ref6.tex b/Doc/ref6.tex index 53e6c403de..70e1a68a63 100644 --- a/Doc/ref6.tex +++ b/Doc/ref6.tex @@ -166,7 +166,7 @@ sequence cannot add new items to a list). If the primary is a mapping (dictionary) object, the subscript must have a type compatible with the mapping's key type, and the mapping is -then asked to to create a key/datum pair which maps the subscript to +then asked to create a key/datum pair which maps the subscript to the assigned object. This can either replace an existing key/value pair with the same key value, or insert a new key/value pair (if no key with the same value existed). @@ -369,7 +369,7 @@ continue_stmt: "continue" \verb@continue@ may only occur syntactically nested in a \verb@for@ or \verb@while@ loop, but not nested in a function or class definition or \verb@try@ statement within that loop.\footnote{Except that it may -currently occur within an \verb@except@ clause.} +currently occur within an {\tt except} clause.} \stindex{for} \stindex{while} \indexii{loop}{statement} diff --git a/Doc/ref7.tex b/Doc/ref7.tex index b8babfb910..f099ae5543 100644 --- a/Doc/ref7.tex +++ b/Doc/ref7.tex @@ -299,7 +299,7 @@ default value is substituted. If a parameter has a default value, all following parameters must also have a default value --- this is a syntactic restriction that is not expressed by the grammar.% \footnote{Currently this is not checked; instead, -\verb@def f(a=1,b)@ is interpreted as \verb@def f(a=1,b=None)@.} +{\tt def f(a=1,b)} is interpreted as {\tt def f(a=1,b=None)}.} \indexiii{default}{parameter}{value} Function call semantics are described in section \ref{calls}. When a diff --git a/Doc/texinputs/copyright.tex b/Doc/texinputs/copyright.tex index f445c40afa..d870d3cab2 100644 --- a/Doc/texinputs/copyright.tex +++ b/Doc/texinputs/copyright.tex @@ -1,5 +1,5 @@ -Copyright 1991, 1992, 1993, 1994 by Stichting Mathematisch Centrum, -Amsterdam, The Netherlands. +Copyright 1991-1995 by Stichting Mathematisch Centrum, Amsterdam, +The Netherlands. \begin{center} All Rights Reserved |