This is to announce bugfix number 2 for GAP 4b5. The priority of this fix
is very high.

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

This fix corrects among other things:
1) An error in the `Intersection' routine for subgroups of FpGroups
2) Potential problems with converting `OperationHomomorphisms' into
`AsGroupGeneralMappingbyImages'.
3) The test for semiregularity is rectified.
4) Several minor errors for rational functions.
5) It adds an improved profile display.
6) It adds a few pieces of functionality that will be required by the first
batch of share packages.
7) The group constructor functions (AbelianGroup &c.) are more robust
against wrong syntax calls.
8) A fix in the test for conjugator automorphisms.

Errors 1,3 and 9 might lead to wrong results.

Many thanks to:
Tom McDonough for reporting errors under 4.

To apply the fix you must have applied bugfixes 1 and 2 first.

Load the zoo archive 'fix4b5n3.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 fix4b5n3.zoo'. `unzoo' may ask you for permissions to overwrite
files, answer this with Y)es or A)ll.

(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 changes the kernel. You have to recompile by calling `make' in the
directory in which you unpacked the fix.

Windows users can find a new binary in the file win4b5f3.zoo in the
`bugfixes' directory.

Macintosh users should download the file bin4b5f3.sit in the `bugfixes'
directory which contains new binaries for both 68k and PPC machines.

You can remove the file 'description3' afterwards.

Alexander Hulpke, 10-Mar-99

#############################################################################
##
## These commands should run without error if the fix has been applied.
##
if not IsSemiRegular(Group((1,2,3)),[1..4]) then
  Error();
fi;
g:=Group((1,2,3),(4,5,6),(1,2),(4,5));IsSolvableGroup(g);
au:=AutomorphismGroup(g);
if ForAny(GeneratorsOfGroup(au),i-> not IsConjugatorAutomorphism(i)) then
  Error();
fi;
f:=FreeGroup(2);
g:=f/[f.1^2,f.2^3,(f.1*f.2)^5];
u:=LowIndexSubgroupsFpGroup(g,TrivialSubgroup(g),5);
v:=LowIndexSubgroupsFpGroup(u[2],TrivialSubgroup(g),5);
R:=Integers;
x:=Indeterminate(R,"x");
y:=Indeterminate(R,"y");
q1:=(x^2+y)^2*x+1;
q2:=(y^2+x)^2*y+1;
r:=Resultant(q1,q2,x);
p1:=7*x^10+120*x^7*y^2+77*x^5*y^2+1132*x^3*y^7+23;
p2:=5*x^11*y+121*x^7*y^3+79*x^7*y^5+1032*x^3*y^7+23;
r:=Resultant(p1,p2,x);
r:=Resultant(q1,q2,x);