PSPP NEWS -- history of user-visible changes. Copyright (C) 1996-2000, 2008-2013 Free Software Foundation, Inc. See the end for copying conditions. Please send PSPP bug reports to bug-gnu-pspp@gnu.org. Changes since 0.8.1: * Charts are now rendered with colours from the Tango palette instead of fully saturated primaries. * Missing values for long string variables are now read from and written to system files in an SPSS-compatible fashion. (Earlier versions of PSPP that supported missing values for long string variables wrote them to system files in an SPSS-incompatible way. To fix the problem, read the system file with this version of PSPP and then save a new copy of it.) Changes from 0.8.0 to 0.8.1: * New commands: - VARIABLE ROLE. * Changes to existing commands: - CROSSTABS: The requirement that one expected count must be less than five before Fishers Exact Test will be reported has been removed. * PSPPIRE graphical user interface improvements: - A new set of icons has been contributed. - Syntax windows now parse syntax in "auto" mode, which in practice should mean that both "batch" and "interactive" syntax now works, instead of just "interactive" syntax. - The variable pane of data windows now include a Role column. * Notable bug fixes: - System files written by IBM SPSS 21 are now read without warnings. - System files written by "VOXCO INTERVIEWER 4.3" are now read without warnings. - PSPPIRE should now more gracefully handle syntax files that contain errors. Changes from 0.6.2 to 0.8.0: * New commands: - ADD FILES - CORRELATIONS - DATAFILE ATTRIBUTES - DATASET ACTIVATE - DATASET CLOSE - DATASET COPY - DATASET DECLARE - DATASET DISPLAY - DATASET NAME - LOGISTIC REGRESSION - MATCH FILES - MEANS - MRSETS - PRESERVE and RESTORE - QUICK CLUSTER - RELIABILITY - ROC - SAVE TRANSLATE to CSV and tab-delimited files - UPDATE - VARIABLE ATTRIBUTES * Changes to existing commands: - AUTORECODE has a new GROUP subcommand. - CROSSTABS has been re-implemented to fix numerous bugs. - EXAMINE: /MISSING=LISTWISE is now the default. - DO REPEAT command has been reimplemented. Now, when DO REPEAT contains an INCLUDE or INSERT command, substitutions are not applied to the included file. - FILE HANDLE has a new ENDS subcommand to select CR or CRLF new-lines. - HOST has been updated to use more modern syntax. - Most commands that work with data files now support a new ENCODING subcommand. - MISSING VALUES can now assign missing values to long string variables. - ONEWAY: the POSTHOC subcommand is now implemented. - The following new subcommands to NPAR TESTS have been implemented: COCHRAN, FRIEDMAN, JONCKHEERE-TERPSTRA, KENDALL, KRUSKAL-WALLIS, MANN-WHITNEY, MCNEMAR, SIGN, WILCOXON, and RUNS - SET and SHOW no longer have ENDCMD, NULLINE, PROMPT, CPROMPT, and DPROMPT subcommands. The defaults are now fixed values. - SHOW now has a JOURNAL subcommand, to show the location of the journal file. - VALUE LABELS can now assign value labels to long string variables. * Other language changes: - The new DATASET commands replace the "scratch file" PSPP extension, which is no longer supported. - Strings may now include arbitrary Unicode code points specified in hexadecimal, using the syntax U'hhhh'. For example, Unicode code point U+1D11E, the musical G clef character, may be expressed as U'1D11E'. See the "Tokens" section in the PSPP manual for more information. - In previous versions of PSPP, in a string expressed in hexadecimal with X'hh' syntax, the hexadecimal digits expressed bytes in the locale encoding. In this version of PSPP, X'hh' syntax always expresses bytes in UTF-8 encoding. See the "Tokens" section in the PSPP manual for more information. * PSPPIRE graphical user interface improvements: - Added support for non-ASCII characters in strings, labels and variable names. - A "Split Window" function is available, which makes it easier to see different parts of a large data file. - Data files can now be opened by specifing their name as the first argument. This means that on a properly configured desktop, double clicking on an icon will open the file. - Foreign formats, such as Gnumeric, OpenDocument and CSV can be imported via using an "intelligent" application assistant dialog. * Output changes: - The new "cairo" output driver supports output in PostScript, PDF, and SVG formats. Its functionality is a superset of that of the "postscript" driver, which has been removed. You must have Cairo and Pango installed to build the "cairo" driver. - Charts are now produced with Cairo and Pango, instead of libplot. Without them, the new graphing features will not work. If you do not have Cairo and Pango installed, you must run `configure' with --without-cairo. - The plain text output driver now properly supports multibyte UTF-8 characters, including double-width characters and combining accents. - Output to OpenDocument format is now supported. - The HTML output is much improved. * The "pspp" program has a new option --batch (or -b) that selects "batch" syntax mode. In previous versions of PSPP this syntax mode was the default. Now a new "auto" syntax mode is the default. In "auto" mode, PSPP interprets most syntax files correctly regardless of their intended syntax mode. See the "Syntax Variants" section in the PSPP manual for more information. * The "pspp" program has a new option --syntax-encoding that specifies the encoding for syntax files listed on the command line, as well as the default encoding for syntax files included with INCLUDE or INSERT. The default is to accept the system locale encoding, UTF-8, UTF-16, or UTF-32, automatically detecting which one the system file uses. See the documentation for the INSERT command in the PSPP manual for more information. * Text data files that PRINT and WRITE creates now use the system native line ends by default (CRLF on Windows, LF only elsewhere). Use the new ENDS subcommand on FILE HANDLE to override the default. * A new Perl module allows Perl programs to read and write PSPP system files. * A tutorial chapter has been added to the user manual. Changes from 0.6.1 to 0.6.2: * New translations: - Dutch, thanks to Harry Thijssen. - Brazilian Portuguese, thanks to Michel Boaventura. Thanks for translations are also due to the coordinators at translationproject.org. * Statistical bug fixes: - REGRESSION: Report correct standard error of the estimate (bug #25677). - T-TEST: Report correct significance of paired sample T-test in the common case (bug #26936) and corner cases. Thanks to Mike Griffiths and Matej Cepl for reporting these bugs. * Build fixes and changes: - Fix build with GTK+ 2.17.4 and later. - Make running "make" after running "configure" with different settings reliably rebuild version.c. - Cygwin and MinGW build fixes. - Fixes for building with recent gnulib. - The Makefile now honors two new variables, PSPP_LDFLAGS and PSPPIRE_LDFLAGS, that affect linking of the PSPP and PSPPIRE binaries, respectively. This makes building easier for some packagers. - Fixes for "configure --enable-relocatable" (bug #25508). * Data file bug fixes and changes: - Fix reading text data files that contain a mix of white space and commas. Now "a ,b" is treated as two fields containing "a" and "b"; previously it was treated as three, with an empty field in the middle. - Fix writing corrupted .sav files on Windows. - Fix writing variable labels longer than 252 bytes to save files. Thanks to Robert Westlund for reporting this bug. - Fix writing corrupted .por files (bug #26034). - Fix reading .por files whose initial lines are not padded out with spaces as expected. - PSPP will no longer issue warnings about some .sav file records or values that it does not understand. These warnings were harmless, but needlessly alarmed some users. - Fix crash reading empty string fields from PostgreSQL databases. * Bug fixes that affect PSPP and PSPPIRE: - Users may now control precision of output statistics. Instead of hard coding the width and decimals of output numbers, respect the default format in most instances. Counts are now normally displayed with the format of the weight variable, if any. - Fix crash when an INSERT command specifies the name of a file that does not exist (bug #24569). - Fix crash when CROSSTABS specifies a long-string variable (bugs #24557 and #26131). - Fix crash drawing pie charts with many segments. - Fix crash when NUMERIC specifies an invalid format. * PSPPIRE bug fixes and changes: - On Windows, write the output file to the user's home directory instead of the current directory, to better match user expectations. - Some data editor fixes. * Documentation: - Fix typo in BINOMIAL section of user manual (bug #25892). Changes from 0.6.0 to 0.6.1: * Statistical bug fixes: - Report correct standardized regression coefficients in linear regression output (bug #23567). * Bug fixes that affect PSPP and PSPPIRE: - Avoid crash with pie charts (bug #24014). - Don't append % to count totals (bug #24003). - Don't crash on bad input (bug #24031). - Don't crash if "end data." is not left aligned (bug #24115). - Change default workspace value to 64 MB, to avoid unnecessary disk accesses on modern machines. * PSPPIRE bug fixes: - Add ".sav" or ".por" suffix to filename when saving with Save_As (bug #23137). - Make it possible to reopen the output window on Windows (bug #24033). - A POSIX regular expression library is now included and used automatically if the host does not have one or has one that is inadequate. * Build fixes and changes: - Work around bug in GSL that prevented build with recent GCC versions without manually adding -fgnu89-inline to CFLAGS. - Also warn about missing prerequisites as we encounter them (bug #24445). - Distribute necessary files to allow users working from the distributed tarball to configure with --enable-gui-tools. - Append $(EXEEXT_FOR_BUILD) to output file name when building q2c, fixing build problems on Windows. - GSL 1.8 or later is now required. - Build errors with --enable-relocatable were fixed. * The German translations were removed, since native German speakers found them too poor to be useful. Changes from 0.4.0 to 0.6.0: * The PSPP license is now version 3 or later of the GNU General Public License. Previously, it was version 2 or later. * PSPP now has a graphical interface, called PSPPIRE. This interface allows you to enter data and variable definitions interactively. Commands may be executed in syntax form, or by using the interactive dialog boxes available from the dropdown menus. * A few sample syntax files are now included in the `examples' directory. * Numerous major and minor bugs have been fixed. Build changes: * The INSTALL file now reflects the details of how to install PSPP. It is a tailored version of the generic installation instructions, instead of a verbatim copy. * iconv, which is ordinarily installed as part of a Unix-like system, is now required. If you don't have it already, you can install GNU libiconv (http://www.gnu.org/software/libiconv/). * libxml2 and zlib are new optional dependencies. They are required to use PSPP's support for reading Gnumeric files. Statistical procedure changes: * REGRESSION is a new procedure for fitting linear models to data via least-squares estimation. * NPAR TESTS is a new procedure for non-parametric tests. In this release, it supports binomial and chi-square tests. * RANK is a new procedure to rank variables. It supports numerous forms of ranking. * FREQUENCIES can now output histograms and pie charts. These features were present in earlier releases, but not documented. User interface changes: * In many situations where PSPP once terminated with a fatal error, PSPP now recovers and continues execution. * PSPP is now able to start up and run even if it cannot find its configuration files. * Journaling of interactive commands to a disk file is now implemented. By default, journaling is enabled, to a file named `pspp.jnl' in the current directory. SET JOURNAL may be used to control journaling. * The use of `+' between syntax file names on the command line to prevent the dictionary from being cleared between their executions is no longer supported. All syntax files are now executed as if `+' had been specified. * The -d/--define and -u/--undef command line options are no longer supported. Instead, use /usr/bin/env or shell primitives to define or clear environment variables before invoking PSPP. * If a syntax file named named `rc' is found in a configuration directory (such as $HOME/.pspp), it is executed before any syntax file specified on the command line. The -r or --no-statrc command line option may be used to disable this behavior. Output changes: * Output configuration options have changed. Please refer to the manual for a full description of the available options. In consequence, you will need to reinstall your "devices" file. "make install" will do this for you. * Most error messages are now written to PSPP output files by default. SET ERROR can be used to disable this behavior. * When invoked interactively, PSPP now by default produces output on the terminal, piping it through the "more" program. Previously, by default output was written only to file pspp.list. On most terminals, the page length used for output automatically adapts to the terminal size, even if the terminal is resized. * ASCII driver: - This driver now supports charts in output. Charts are written as separate files that the main output file refers to. By default, charts are written in PNG format to files named pspp-1.png, pspp-2.png, and so on. - Configurations are provided that use VT100 (and xterm) line-drawing characters in tables. The option "-o list-vt100" requests use of this device for output to pspp.list. * PostScript driver: - The default paper size is now determined using the PAPERSIZE environment variable, or the LC_PAPER locale category on systems that support it. If these are not set, the default is now A4, instead of US letter. To make US letter the default, set PAPERSIZE to "letter" in your environment. - Font metrics are now read from AFM files, instead of Groff-format metrics files. PostScript fonts can now be embedded in output. In consequence, you will need to install an AFM file for each font used in PostScript output. "make install" will install AFM files for the standard PostScript fonts, including the ones that the PostScript driver uses by default. - Standard paper sizes no longer need to be specified through a configuration file. The "papersize" configuration file is no longer needed, or supported. - The PostScript prologue is no longer obtained from the "ps-prologue" configuration file. This configuration file is no longer needed, or supported. * HTML driver: - The HTML prologue is no longer obtained from the "html-prologue" configuration file. This configuration file is no longer needed, or supported. Command language changes: * The following commands are new: - GET DATA, which currently supports reading Gnumeric files and text data files. It will be extended later to read other types of foreign data. - CD, to change the current directory. - INSERT, to execute a syntax file. - DELETE VARIABLES, to remove variables from the active file dictionary. - ADD DOCUMENT, to add text to active file documents. - CLOSE FILE HANDLE (a PSPP extension; see below). - XEXPORT, a PSPP extension that is a transformation equivalent to EXPORT. * The following functions for transformation expressions are new: - DATEDIFF, for computing the difference of two dates. - DATESUM, for advancing a date by a specified duration. - VALUELABEL, to obtain the value label for a value. * PSPP now supports very long string variables (over 255 bytes long). * MATCH FILES now supports the FIRST and LAST subcommands. * Previous versions of PSPP prohibited using commands to both read and write a single file at the same time. Now, PSPP allows this, and the new version of the file atomically replaces the old version. * The following commands are no longer available. They will be re-implemented in a later release: - CLEAR TRANSFORMATIONS - MATRIX DATA - REPEATING DATA * The PROCESS IF command, which was deprecated, has been removed. You may replace any usage of it by SELECT IF following TEMPORARY, which has the same effect. * The output format for variables created by VECTOR may now be specified as part of the VECTOR syntax. "Scratch files", a new PSPP extension: A scratch file, like a system file, consists of a dictionary and any number of cases. Small scratch files are stored in memory; one that grows too large is written to disk. By default, any file handle whose name begins with # is assumed to refer to a scratch file. Scratch files can be used just about anywhere a system or portable file can be used. Also, portable files are now allowed in most places that system files were allowed in previous PSPP version. A new CLOSE FILE HANDLE command allows the storage associated with scratch files to be freed. It also allows file handles to be reassigned to new files. For more information on scratch files, refer to the "File Handles" section in the PSPP manual. For specifics of what commands now allow what kinds of files to be specified, refer to the documentation on those particular commands. Data access changes: * Binary formats and IBM/360 formats, including ASCII/EBCDIC translation, are now supported. Use FILE HANDLE to specify the format of these files. * Little-endian, big-endian, and VAX-endian formats are now supported for integer binary formats when reading and writing data files. The new RIB and WIB subcommands on the SET command control endianness of integer data. The default is the host's native endianness. * IEEE 754, VAX, and IBM hexadecimal formats are now supported for floating point binary formats when reading and writing data files. The new RRB and WRB subcommands on the SET command control the floating point format. The default is the host's native floating point format. * DATA LIST now supports the SKIP subcommand, to skip records at the beginning of a file. For compatibility, DATA LIST now treats N format as F format for FREE and LIST format input. * The SAVE and XSAVE commands now support the UNSELECTED, PERMISSIONS, NAMES, and MAP subcommands. * The EXPORT command has been re-implemented to obtain better results. Support for the UNSELECTED, DIGITS, and TYPE subcommands has been added. * For compatibility, PRINT now inserts a space at the beginning of every output line, even lines that would otherwise be blank, when OUTFILE is specified. (The behavior of WRITE is unchanged.) * For compatibility, PRINT EJECT now inserts the digit `1' at the beginning of each line that should begin a new page. * For compatibility, WRITE now outputs the system-missing value as a field filled with spaces. Binary formats are an exception. (The behavior of PRINT is unchanged.) Documentation: * Input and output format descriptions have been rewritten. They now precisely describe what is accepted on input and written on output. * The descriptions of the PSPP system and portable file formats have been extensively revised and improved. For developers, the build system now requires Autoconf 2.60 and Automake 1.10. Changes from 0.3.0 to 0.4.0: Changes in build dependencies: * The GNU Scientific Library (libgsl), version 1.6 or later, is now required. * libplot from GNU plotutils is optional. Without it, the new graphing features will not work. If you do not have it installed, you must run `configure' with --without-libplot. * libgmp2 is no longer a dependency. Newly implemented commands and statistical features: * EXAMINE, including its graphing features. * FREQUENCIES now supports percentiles. * ONEWAY. * PERMISSIONS. * SHOW. * SORT CASES now sorts stably, that is, two cases with equal sort criteria will be in the same relative order before and after the sort. * T-TEST (re-written). * DATE and USE. These commands are parsed but otherwise ignored, to enhance compatibility with certain command files that invoke them unnecessarily. * VARIABLE WIDTH, VARIABLE ALIGNMENT, and VARIABLE LEVEL. These currently have no effect on PSPP output, but their values are written to and read from system files and thus may affect third-party software. * SET EPOCH implemented. * DATA LIST FREE and DATA LIST LIST now support arbitrary field delimiters. * FILE HANDLE now supports custom tab widths. Long variable names (and other identifiers) are now supported. Up to the first 64 bytes of each identifier is significant. PSPP now reads and writes system files compatible with SPSS version 12. New --algorithm and --syntax command line options allow SPSS-compatible or enhanced modes to be selected. Support for transformation expressions has been rewritten and significantly improved. Refer to the manual for details. Calculation of moments (mean, standard deviation, kurtosis, skewness) has been rewritten and should now be more accurate. In --algorithm=enhanced mode moments may be more accurate than SPSS in some cases. Numerous bugs have been fixed, too many to mention here. Many new tests have been added, leading to the discovery and fixing of many of these bugs. The ASCII output driver can now squeeze multiple blank lines into single blank lines. Much of the code has been rewritten and refactored. It is now much cleaner. The FILE TYPE and REPEATING DATA commands have been disabled for this release because their implementations were deemed too buggy to be useful. They will be fixed and replaced in a future release. New pspp-mode for Emacs (in pspp-mode.el). Added rudimentary command-line completion for interactive input. lib/julcal and lib/dcdflib are no longer used, so they have been removed. For developers, the build system now requires Autoconf 2.58 and Automake 1.7. The included gettext has been updated to version 0.12.1. Some reports state that Texinfo 4.8, the latest version, may be necessary to successfully format the documentation on some systems. Version 0.3.0 changes since 0.2.3: Bugs fixed: * Using alphanumeric variables in functions under AGGREGATE segfaulted. Fixed. * Under certain circumstances, the final case would be omitted from the results of an AGGREGATE operation. Fixed. * Undefined behavior was invoked by referencing a freed pointer under certain circumstances. Fixed. * A wrong record size was displayed when paging the active file to disk. Fixed. * Not having enough temporary space for sorting caused a core dump. Fixed. * Syntax errors in function descriptions on AGGREGATE caused core dumps. Fixed. * A null pointer was dereferenced, causing a core dump, when PERCENTILES was specified on FREQUENCIES. This fixes the problem, but PSPP still doesn't calculate percentiles. * SORT always sorted in ascending order. Fixed. * Some minor memory leaks in the expression parser were removed. * Many assertions fixed for strict ANSI C compliance. New features: * SET ECHO ON now implemented, but turned off by default. * PRINT specifier supported on END REPEAT. Other: * System libgmp2 library is used if installed instead of unconditionally using the included libgmp2 subset. * Extensive code cleanup, which continues. * Added CORRELATIONS command parser, but not implemented. Version 0.2.3 changes since 0.2.2: Bugs fixed: * SPLIT FILE with a string variable caused a core dump. Fixed. * Nested INCLUDEs didn't work. Fixed. * The MATCH FILES procedure set the values of variables not present to 0. It should have been SYSMIS. This is now fixed. * The REMARK command was too aggressive about skipping lines. It didn't like being the last command in a file. * Comment parsing wasn't consistent with the rest of the code in its idea of where one command ends and another starts. This meant that sometimes commands would be mysteriously ignored. Thanks to Dr. Dirk Melcher for reporting this bug. * The TABLE subcommand on MATCH FILES worked only erratically at best. This fixes it. Thanks to Dr. Dirk Melcher for reporting this bug. * VARIABLE LABELS rejected a slash before the first variable specification, contradicting the documentation. Thanks to Walter M. Gray for reporting this bug. * Because of an incorrect optimization in memory allocation, CROSSTABS sometimes segfaulted when asked to output multiple tables. Thanks to Walter M. Gray for reporting this bug. * CROSSTABS didn't display value labels for column and row variables. Thanks to Walter M. Gray for reporting this bug. * WRITE didn't write line ends. Fixed. Thanks to Dr. Dirk Melcher for reporting this bug. * The TABLE subcommand on MATCH FILES worked only erratically at best. This fixes it. Thanks to Dr. Dirk Melcher for reporting this bug. * VARIABLE LABELS rejected a slash before the first variable specification, contradicting the documentation. Thanks to Walter M. Gray for reporting this bug. * Because of an incorrect optimization in memory allocation, CROSSTABS sometimes segfaulted when asked to output multiple tables. Thanks to Walter M. Gray for reporting this bug. * CROSSTABS didn't display value labels for column and row variables. Thanks to Walter M. Gray for reporting this bug. * WRITE didn't write line ends. Fixed. Thanks to Dr. Dirk Melcher for reporting this bug. * MATCH FILES corrupted memory and dumped core on some syntax errors. Fixed. * MATCH FILES should set numeric values not available to the system-missing value, not to 0. Thanks to Dr. Dirk Melcher for reporting this bug. * KEEP didn't work properly on the SAVE procedure. Fixed. Thanks to Ralf Geschke for reporting this bug. * Memory leak fix. * Some systems didn't like the way open_file was coded. Thanks to Hankin for pointing this out. * The SAVE procedure didn't save long string variables properly. Fixed by this patch. Thanks to Hankin for this patch. * Minor documentation fixes for MATCH FILES. Version 0.2.2 changes since 0.2.1: Bugs fixed: * Fix behavior of PRINT SPACE for negative arguments. * Fix reading some unusual system files. * Fix LIST problems with very long variables. Thanks to Hankin for this bug report. * Fix problems with some string format specifiers. * Fix use of $CASENUM in expressions. Thanks to Dirk Melcher for reporting this bug. * Additional DATA LIST FREE and DATA LIST LIST fixes. Thanks to Hankin again on this one. * Sometimes you may encounter a PSPP script that has to be interpreted in interactive mode. Now you can use the -i flag to do this. * Warnings for egcs 1.1.1 cleaned up. (However you'll get lots of `unused variable' warnings under gcc 2.7.2.3, fixing this will take more effort.) * Tests fixed. * The files in gmp need the internationalization directory in their include path. Thanks to OKUJI Yoshinori for pointing this out. Version 0.2.1 changes since 0.2.0: Bugs fixed: * Remember to include examples/ directory in distribution :-) * Fixed gmp compile problems for some non-i386 architectures. Thanks to Hans Olav Eggestad and others for reporting this. * DATA LIST FREE and DATA LIST LIST parsing of input files is now matches the documented behavior exactly, and error messages are more helpful. Thanks to Mark H. Wood . Version 0.2.0 changes since 0.1.0: Procedures now implemented: * CROSSTABS. Please see documentation for caveats. Transformations and utilities now implemented: * AGGREGATE * APPLY DICTIONARY * CLEAR TRANSFORMATIONS * DISPLAY (all subcommands). * ERASE * FLIP * EXPORT * HOST * IMPORT * MATCH FILES * MATRIX DATA * NEW FILE * REPEATING DATA Support for input and output through pipes: "|command" and "command|" filenames; support for special filenames "-", "stdin", "stdout", "stderr". New command-line features: * New option --testing-mode: Invoke heuristics to assist testing. * New option --safer, -s: Don't allow certain unsafe operations. * New option --command=CMD, -c CMD: Perform literal command CMD. * rc file ~/.pspp/rc is executed before any other files. * Now multiple syntax files can be specified. Operator LAG is now implemented. Added missing FILE subcommand to REREAD. Table output manager completely rewritten. Device configuration file syntax changed. You will need to reinstall your `devices' file. New output driver for HTML. PostScript driver and prologue simplified. Many bugs fixed. General source-code cleanup. Added Texinfo documentation for: * PSPP system file format * PSPP portable file format * How to write input for q2c parser generator * HTML driver PSPP language is now fully documented. Please report any inaccuracies or omissions in the documentation. Changes for version 0.1.0: First public release. For changes from unreleased development versions, please see ONEWS. ---------------------------------------------------------------------- Copyright information: Permission is granted to anyone to make or distribute verbatim copies of this document as received, in any medium, provided that the copyright notice and this permission notice are preserved, thus giving the recipient permission to redistribute in turn. Permission is granted to distribute modified versions of this document, or of portions of it, under the above conditions, provided also that they carry prominent notices stating who last changed them. Local variables: version-control: never mode: indented-text end: