AboutHap

#### Download Instructions On a Linux machine with GAP installed, the HAP library can be loaded as follows: First download the file hap1.7.tar.gz to the subdirectory "pkg/" of GAP. (If you don't have access to this, then create a directory "pkg" in your home directory and download the file there.) Change to directory "pkg/" and type "gunzip hap1.7.tar.gz" followed by "tar -xvf hap1.7.tar" . Start GAP. (If you have created "pkg" in your home directory then start GAP with the command "gap -l 'path/homedir;' " where path/homedir is the path to your home directory.) In GAP type " LoadPackage("HAP"); " Help on HAP can be found on the HAP home page (a version of which is included in directory "pkg/Hap1.7/www" of the distribution). A few of HAP's (optional) functions rely on Polymake software (available from www.math.tu-berlin.de/polymake/) which should be installed so that it starts using the command "polymake" at the Linux prompt. A few (optional) functions rely on Graphviz software (available from http://www.graphviz.org/). Performance can be improved by using a compiled version of the HAP library. The following steps will produce a compiled version. (1) Change to the directory "pkg/Hap1.7/" . (2) Edit the file "compile" so that: PKGDIR is equal to the path to the directory "pkg" where your GAP packages are stored; GACDIR is equal to the path to the directory where the GAP compiler "gac" is stored. (3) Type "./compile" . The next time HAP is loaded a compiled version will be loaded. Should you want to return to an uncompiled version, change to the directory "pkg/Hap1.7/" and type "./uncompile".
#### Changes Log Version 1.4 was released on 03/05/2006. Version 1.5 was released on 12/06/2006. GAP types were introduced for resolutions, chain complexes etc. and methods for PrintObj and ViewObj were introduced. The functions Homology and Cohomology where changed to GAP operations. A Linux shell script "compile" for creating a GAC compiled version of the HAP functions was added. The performance of the functions NonabelianTensorSquare() and ResolutionPrimePowerGroup() was improved. Functions ResolutionSubnormalSeries(), ResolutionAlmostCrystalGroup() and ResolutionAlmostCrystalQuotient() were added. Version 1.6 was released on 15/08/2006. The functions Honology(), Cohomology() and PrimePartDerivedFunctor() have been speeded up. Graphviz is now used to visualize Coxeter diagrams, Graphs of groups and Cayley graphs. The functions ResolutionGraphOfGroups(), ChevalleyEilenbergComplex(), LieAlgebraHomology, LowerCentralSeriesLieAlgebra(), ModPCohomologyRing(), ModPRingGenerators have been included. Version 1.7 was released on 01/09/2006. The functions Epicentre() and IsGraphOfGroups() were renamed EpiCentre() and GraphofGroupsTest() due to name clashes arising from recent modifications to GAP. A minor modification was made to the functions NonabelianTensorSquare() and ThirdHomotopyGroupOfSuspensionB() so that they run on nilpotent infinite groups when the NQ package is loaded.