Dear Gap Forum,

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

You should not apply this fix to any version of GAP3.
To apply the fix, you must have installed bugfixes 1 to 3 first.

This fix corrects:
1) An error in `MolienSeries' calling `UnivariatePolynomial'
2) An error in `Symmetrizations'
3) A problem with `Operation' acting on non-homogeneous sets.
4) An error in the idempotent routine.
5) A problem with group algebras.
6) An error in the meataxe.

All these problems lead to error messages.

Many thanks to:
Jacob Hirbawi for reporting errors 1 and 2,
Leonard Soicher for reporting error 3,
Craig Struble for reporting error 4.
Richard Rossmanith for reporting error 5.
Derek Holt for substantial help with fixing error 6.

Load the zoo archive 'fix4b4n4.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 fix4b4n4.zoo'
(On a PC or a Mac you will have to copy `unzoo' in the same directory and
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.

You can remove the file 'description4' afterwards.

Alexander Hulpke, 9-Oct-98

#############################################################################
##
## These commands should run without error if the fix has been applied.
##
act:=function(x,g)
 if not IsSet(x[1]) then
  return OnSets(x,g);                
 else
  return OnSetsSets(x,g);
 fi;
end;
P:=[[1,2],[3,4]];
G:=SymmetricGroup(4);  
L:=Union(Orbits(G,[[1,2,3],[[1,2],[3,4]]],act));;
GG:=Operation(G,L,act); 

g := SymmetricGroup(3); f := GF(7);
fg := FreeMagmaRing(f, g);
CentralIdempotentsOfAlgebra(fg);

# if you do not have the character tables library installed, the following
# tests cannot be executed. Simply ignore them.
chr:=CharacterTable("PSL(2,7)");;
irr:=Irr(chr);;
MolienSeries(chr,irr[3],irr[1]);
MolienSeries(chr,irr[3],irr[2]);
chr:=CharacterTable("PSL(2,7)");;
irr:=Irr(chr);;
Symmetrizations(chr,[irr[3]],3);