> < ^ Date: Wed, 24 Feb 1993 12:26:10 +0100
> ^ From: Volkmar Felsch <Volkmar.Felsch@Math.RWTH-Aachen.DE >
< ^ Subject: Re: Change List

Yesterday, Thomas Breuer has already given a first answer to Steve
Linton's question

Is there a comprehensive list of changes from 3.1 to 3.2?

I would like to add to his list a few more remarks concerning changes
and extensions of functions described in the manual chapters "Groups",
"Table of Marks", "Finite Polycyclic Groups", and "Finitely Presented
Groups".

Chapter "Groups"
----------------

Facilities for computing and printing the subgroup lattice of a
given group have been added, and an explicit description of the
respective new functions

Lattice
PrintClassSubgroupLattice
SetPrintLevel

has been added to the manual setcion.

The description of the TableOfMarks function has been removed from
the setcion and moved to an own chapter.

Chapter "Table of Marks"
------------------------

The function TableOfMarks to compute Burnside's table of marks of a
finite group has been changed and extended by several new functions
for handling such tables. The new chapter "Table of Marks" describes
all these functions:

TableOfMarks
Marks
NrSubs
WeightsTom
MatTom
TomMat
DecomposedFixedPointVector
TestTom
DisplayTom
NormalizerTom
IntersectionsTom
IsCyclicTom
FusionCharTableTom
PermCharsTom
MoebiusTom
CyclicExtensionsTom
IdempotentsTom
ClassTypesTom
ClassNamesTom
TomCyclic
TomDihedral
TomFrobenius

Chapter "Finite Polycyclic Groups"
----------------------------------

Since the release of version 3.1 some functions have been renamed or
replaced by global functions:

pQuotient -> PQuotient, PrimeQuotient
pQpresentationSave -> Save
pQpresentationRestore -> PQp
pQpresentationPrint -> Print
pQInit -> InitPQp
pQWeight -> Weight
NextClass -> NextClassPQp
pAbelianQuotient -> FirstClassPQp
DefiningGenerators -> Factorization

They are now properly described in the GAP 3.2 manual release.

Chapter "Finitely presented group"
----------------------------------

This chapter has been extended by six sections which describe new
functions for handling group presentations. As GAP does never allow
to alter any presentation which is part of a group record, we have
introduced so called "presentation records" as a new type of GAP
objects which are permitted to be changed. The functions

PresentationFpGroup
FpGroupPresentation
TzPrintStatus
TzPrintGenerators
TzPrintRelators
TzPrintPresentation
TzPrint
TzPrintLengths
TzPrintPairs
TzPrintOptions
Save
AddGenerator
AddRelator
RemoveRelator

allow to create, administrate, print, or alter such pressentation
records. In particular, Tietze transformations can be applied to
them via the functions

SimplifiedFpGroup
SimplifyPresentation
TzGo
TzGoGo
TzEliminate
TzSearch
TzSearchEqual
TzFindCyclicJoins
TzSubstitute
TzSubstituteCyclicJoins

Moreover, we offer new functions

PresentationSubgroup
PresentationSubgroupMtc
PresentationSubgroupRrs
PresentationNormalClosure
PresentationNormalClosureRrs
DecodeTree

for computing a presentation of a subgroup of a finitely presented
group using the so called Modified Todd-Coxeter method or the
Reduced Reidemeister-Schreier algorithm.

I hope these remarks will be another help in figuring out at least
some features which are new in GAP 3.2 .

Volkmar Felsch


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