> < ^ Date: Tue, 02 Jul 1996 10:34:00 +0100 (MET)
> < ^ From: Frank Celler <frank.celler@math.rwth-aachen.de >
^ Subject: BUGFIX #19 (serious problem in 'GroupId')

This mail contains a bugfix for a serious problem in GAP 3.4.3. You
should apply this bugfix soon if you are using 'GroupId'. The problem
is in 'GroupId' and causes it to fail for one group of size 100.

HOW TO APPLY

The problem is a serious problem, because it may cause a computation to
fail. Thus the bugfix has medium priority, and we recommend that you
apply it soon if you are using 'GroupId'.

Go to the GAP directory (the directory with the 'grp/' subdirectory),
name this mail 'bugfix19.dif', and issue the command:

patch -p0 < bugfix19.dif

If 'patch' writes "I can't seem to find a patch in there" try 'patch -v'.
If 'patch -v' gives an error message or reports a version older than 2.1,
get 2.1 from 'ftp://FTP.Math.RWTH-Aachen.DE/pub/gap/utils/patch2_1.zoo'.

This bugfix changes only the group library. Thus you need not recompile
the GAP kernel.

VERSION

GAP 3.4.3.0

DESCRIPTION

'GroupId' fails for the 16th solvable group of size 100 and signals

gap> GroupId( SolvableGroup( 100, 16 ) );
Error, List Element: <list>[16] must have a value at
return rec(
    catalogue := [ 100, nr ],
    names := GroupIdOps.GroupName100[nr],
    size := 100 ) ... in
GroupIdOps.Group100( G ) called from
G.operations.GroupId( G ) called from
GroupId( SolvableGroup( 100, 16 ) ) called from
main loop

CORRECT BEHAVIOUR

gap> GroupId( SolvableGroup( 100, 16 ) );
rec(
  catalogue := [ 100, 16 ],
  names := [ "25:4" ],
  size := 100 )

COMMENT

The list of names for the solvable groups of size 100 was not correct.

PATCH

--- grp/groupid.grp     Thu Dec 21 14:25:34 1995
+++ grp/groupid.grp     Thu Jun 27 09:48:33 1996
@@ -3,7 +3,7 @@
 #A  groupid.grp                 GAP group library                Frank Celler
 #A                                                         & Hans-Georg Esser
 ##
-#A  @(#)$Id: 1.html,v 1.2 2004/04/21 15:03:31 felsch Exp $
+#A  @(#)$Id: 1.html,v 1.2 2004/04/21 15:03:31 felsch Exp $
 ##
 #Y  Copyright 1990-1992,  Lehrstuhl D fuer Mathematik,  RWTH Aachen,  Germany
 ##
@@ -13,6 +13,9 @@
 ##  the R.Laue Catalogue of groups of order 96.
 ##
 #H  $Log: 1.html,v $
 #H  Revision 1.2  2004/04/21 15:03:31  felsch
 #H  Corrected links in the Forum Archive pages.   VF
 #H
 #H  Revision 1.1.1.1  2004/04/20 13:39:31  felsch
 #H  The final GAP-Forum archive until 2003.
 #H
 #H  Revision 1.4  2003/06/12 19:20:34  gap
 #H  Further update. AH
 #H
 #H  Revision 1.3  1997/08/15 11:19:38  gap
 #H  New forum setup. AH
 #H
 #H  Revision 1.2  1997/04/24 15:33:16  gap
 #H  These files were replaced by the versions in WWW. The content is basically the
 #H  same but the formatting has been much more friendly towards the HTML-Converter.
 #H  AH
 #H
 #H  Revision 1.1  1996/10/30 13:07:07  gap
 #H  added forum archive and translation files.
 #H
+#H  Revision 3.6.1.3  1996/06/27 07:48:02  fceller
+#H  added missing name for 16th group of order 100
+#H
 #H  Revision 3.6.1.2  1994/08/18  16:01:56  fceller
 #H  added '3primes' for small groups
 #H
@@ -2699,7 +2702,7 @@
 GroupIdOps.GroupName100 := [
     ["10^2"], ["50x2"], ["5x20"], ["100"], ["10xD10"], ["5x10.2"],
     ["5x5:4"], ["2x5^2:2"], ["(5^2x2).2"], ["D100"], ["50.2"],
-    ["D10^2"], [], [], [] ];
+    ["D10^2"], [], [], [], ["25:4"] ];

 GroupIdOps.GroupList100 := [
     [ 1, 1, 2, 3, 5, 24, 10, 72 ],
END OF  bugfix19.dif ________________________________________________________

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