Dear Gap Fo(u)rum,

This is to announce bugfix number 3 for GAP 4b4. The priority of this fix
is medium.

You should not apply this fix to any version of GAP3.

This fix corrects:
1) `Operation' on the empty set.
2) A bug in `Resultant'
3) An error in the way how GAP determines the operating system.
4) A potential problem in the code which computes a CGS wrt. a modulo Pcgs.
5) A problem with displaying the default `help' message.
6) An error in the arithmetic for univariate rational functions.

Errors 1,2, 5 and 6 lead to error messages, error 3 will display a warning
(under Windows) when leaving GAP.

Many thanks to:
Leonard Soicher for reporting error 1, Giovanni Cutolo for reporting error 2,
Rubi Rodriguez for reporting error 3, Craig Struble for reporting error 5
and Jacob Hirbawi for reporting error 6.

To apply the fix, you must have installed bugfixes 1 and 2 first.
Load the zoo archive 'fix4b4n3.zoo' from the bugfixes web page
http://www-gap.dcs.st-and.ac.uk/~gap/Info4/bugfixes.html
Alternatively you can find this file in the 'bugfixes' directory of the
GAP4 ftp distribution.

Unpack the file in the home directory of your GAP distribution (the
directory containing the 'lib' and 'grp' directories) using
'unzoo -x fix4b4n3.zoo'
(On a PC or a Mac you will have to enter the argument line after
the call to 'unzoo'.) This will replace the erraneous file by fixed versions.
Make sure you have write permissions when applying the fix.

This fix does not change the kernel. You do not need to recompile. (Windows
users however should get the latest compiled binary in the file
`winbin2a.zoo' from the bugfixes page.)

You can remove the file 'description3' afterwards.

Alexander Hulpke, 2-Sep-98

#############################################################################
##
## These commands should run without error if the fix has been applied.
##
Operation(SymmetricGroup(2),[],OnSets);
Operation(SymmetricGroup(2),[[]],OnSets);
x:=Indeterminate(Rationals);
Resultant(x^2+1,x+1,1);
X:=Indeterminate(GF(5));
Resultant(X^3+X^0, X^2,X);
X*5;
chr:=CharacterTable("PSL(2,7)");
irr:=Irr(chr);;
s1:=MolienSeries(chr,irr[1]);
s2:=MolienSeries(chr,irr[2]);
s4:=MolienSeries(chr,irr[4]);