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GAP 4.4 Update 10 (October 2007)
New or improved functionality
1. Files in the 'cnf' directory of the GAP
distribution are now archived as binary files. Now
GAP can be installed with UNIX or with WINDOWS
style line breaks on any system and should work
without problems.
2. Since large finite fields are available, some
restrictions in the code for computing irreducible
modules over finite fields are no longer
necessary. (They had been introduced in order to
give better error messages.)
3. Made PositionSublist faster in case the search
string does not contain repetitive patterns.
4. The function MakeImmutable now returns its
argument.
5. Dynamically loaded modules now work on Mac OS X.
As a consequence, this allows to work with the
Browse, EDIM and IO packages on Mac OS X.
6. Introduced ViewObj and PrintObj methods for
algebraic number fields. Made them applicable to
AlgebraicExtension by adding the property
IsNumberField in the infinite field case.
7. The function CharacterTableRegular is
documented now.
8. The function ScalarProduct now accepts also
Brauer characters as arguments.
9. The function QuaternionAlgebra now accepts
also a list of field elements instead of a field.
Also, now the comparison of return values (w.r.t.
equality, containment) yields true if the
parameters coincide and the ground fields fit.
10. The function RemoveCharacters is now
documented.
11. Lists in GAP sometimes occupy memory for possible
additional entries. Now plain lists and strings
read by GAP and the lists returned by List
only occupy the memory they really need. For more
details see the documentation of the new function
EmptyPlist.
12. There are some new Conway polynomials in
characteristic 2 and 3 provided by Kate Minola.
13. A new operation MemoryUsage determines the memory
usage in bytes of an object and all its
subobjects. It does not consider families and
types but handles arbitrary selfreferential
structures of objects.
Fixed bugs which could produce wrong results
1. When forming the semidirect product of a matrix
group with a vector space over a nonprime field
the embedding of the vector space gave a wrong
result. [Reported by anvita21]
2. DefaultRing failed for constant polynomials over
nonprime fields. [Reported by Stefan Kohl]
3. The method in ffeconway.gi that gets coefficients
WRT to the canonical basis of the field from the
representation is only correct if the basis is
over the prime field. Added a TryNextMethod if
this is not the case. [Reported by Alla Detinko]
4. Creating a large (>2^16) field over a nonprime
subfield went completely wrong. [Reported by Jack
Schmidt, from Alla Detinko]
5. A method for Coefficients for Conway polynomial
FFEs didn't check that the basis provided was the
canonical basis of the RIGHT field. [Reported by
BE]
6. An elementary abelian series was calculated
wrongly. [Reported by N. Sieben]
7. Orbits on sets of transformations failed.
8. Wrong methods for GeneratorsOfRing and
GeneratorsOfRingWithOne have been removed.
These methods were based on the assumption that
one can obtain a set of ring generators by taking
the union of a known set of field generators, the
set of the inverses of these field generators
and {1}.
9. The name of a group of order 117600 and degree 50
was incorrect in the Primitive Permutation
Groups library. In particular, a group was wrongly
labelled as PGL(2, 49).
10. There was a possible error in
`SubgroupsSolvableGroup' when computing subgroups
within a subgroup.
11. An error in 2Cohomology computation for pc groups
was fixed.
12. `IsConjugate' used normality in a wrong supergroup
Fixed bugs which could lead to crashes
1. GAP crashed when the PATH environment variable was
not set. [Reported by Robert F. Morse]
2. GAP could crash when started with option x 1. Now
the number of columns is initialized with at
least 2. [Reported by Robert F. Morse]
3. After loading a saved workspace GAP crashed when
one tried to slice a compressed vector over a
field with 2 < q <= 256 elements, which had
already existed in the saved workspace. [Reported
by Laurent Bartholdi]
4. FFECONWAY.WriteOverSmallestCommonField tripped up
when the common field is smaller than the field
over which some of the vector elements are
written, because it did a test based on the degree
of the element, not the field it is written over.
[Reported by TB]
5. Fixed the following error: When an FFE in the
Conway polynomial representation actually lied in
a field that is handled in the internal
representation (eg GF(3)) and you tried to write
it over a bigger field that is ALSO handled
internally (eg GF(9)) you got an element written
over the larger field, but in the Conway
polynomial representation, which is forbidden.
[Reported by Jack Schmidt]
6. Attempting to compress a vector containing
elements of a small finite field represented as
elements of a bigger (external) field caused a
segfault. [Reported by Edmund Robertson]
7. GAP crashed when BlistList was called with a range
and a list containing large integers or
nonintegers. [Reported by Laurent Bartholdi]
8. GAP no longer crashes when OnTuples is called with
a list that contains holes. [Reported by TB]
Other fixed bugs
1. `Socle' for the trivial group could produce an
error message.
2. DirectoryContents ran into an error for
immutable strings without trailing slash as
argument. [Reported by TB]
3. The functions IsInjective and
IsSingleValued did not work for general linear
mappings with trivial (pre)image. [Reported by
Alper Odabas]
4. Creating an enumerator for a prime field with more
than 65536 elements ran into an infinite
recursion. [Reported by Akos Seress]
5. The performance of List, Filtered, Number, ForAll,
and ForAny if applied to noninternally
represented lists was improved. Also the
performance of iterators for lists was slightly
improved.
6. Finite field elements now know that they can be
sorted easily which improves performance in
certain lookups.
7. A method for IsSubset was missing for the case
that exactly one argument is an inhomogeneous
list. [Reported by Laurent Bartholdi]
8. Long integers in expressions are now printed (was
not yet implemented). [Reported by TB]
9. Fixed kernel function for printing records.
10. New C library interfaces (e.g., to ncurses in
Browse) need some more memory to be allocated with
'malloc'. The default value of GAPs 'a' option is
now '2m'.
11. Avoid warnings about pointer types by newer gcc
compilers.
12. IsBound(l[pos]) was failing for large integer
<pos> only when coded (eg in a loop or function
body).
13. ZmodpZObj is now a synonym for ZmodnZObj such that
from now on such objects print in a way that can
be read back into GAP.
14. The outdated note that binary streams are not yet
implemented has been removed.

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