<!-- ------------------------------------------------------------------- -->
<!-- -->
<!-- intro.xml KAN documentation Chris Wensley -->
<!-- & Anne Heyworth -->
<!-- ------------------------------------------------------------------- -->
<?
xml version=
"1.0" encoding=
"UTF-8"?>
<Chapter Label=
"intro">
<Heading>Introduction</Heading>
The &kan; package started out as part of Anne Heyworth
's thesis
<Cite Key=
"anne-thesis" />, and was designed to compute
induced actions of categories (see also <Cite Key=
"BrHe" />).
<P/>
This
version of &kan; only provides functions for the computation of
normal forms of representatives of double cosets of finitely presented groups,
and is made available in support of the paper <Cite Key=
"BrGhHeWe" />.
Existing methods for computing double cosets in &GAP; are described
in <Cite Key=
"SteveL" />.
<P/>
The package is loaded into &GAP; with the command
<Example>
<![
CDATA[
gap> LoadPackage(
"kan" );
]]>
</Example>
The package may be obtained as a compressed tar file
<File>kan-version.number.tar.gz</File>
by ftp from one of the following sites:
<List>
<Item>
the &kan; GitHub site:
<
URL>
https://github.com/gap-packages.github.io/kan/</
URL>.
</Item>
<Item>
any &GAP; archive, e.g.
<
URL>
https://www.gap-system.org/Packages/packages.html</
URL>;
</Item>
</List>
The package also has a GitHub repository at:
<
URL>
https://github.com/gap-packages/kan/</
URL>.
<P/>
Some of the functions in the &Automata; package
are used to compute word acceptors and regular expressions
for the languages they accept.
<P/>
The <Package>KBMag</Package> package is also used
to compute a word acceptor of a group <C>G</C>
when <C>G</C> has no finite rewriting system.
If <Package>KBMag</Package> is not available
(the user is not on a UNIX system, or the C-programs have not been compiled),
the file <File>dckbmag.gi</File> will not be read,
so methods for the functions detailed in section 2.4.1 will not be available.
<P/>
Once the package is loaded, it is possible to check the installation
is correct by running a test file of the manual examples with the
following command.
(The test file itself is <F>tst/fulltest.tst</F> or <F>tst/parttest.tst</F>,
depending whether or not <Package>KBMag</Package> is available.)
<Example>
<![
CDATA[
gap> ReadPackage(
"kan",
"tst/testall.g" );
#I Testing /Applications/gap/my-dev/pkg/kan/tst/fulltest.tst
#I No errors detected while testing package kan
true
]]>
</Example>
<P/>
The information parameter <C>InfoKan</C> takes default value <C>0</C>.
When raised to a higher value, additional information is printed out.
<P/>
Once the package is loaded, the manual <Code>doc/manual.pdf</Code>
can be found in the documentation folder.
The <Code>
html</Code> versions, with or without MathJax,
may be rebuilt as follows.
<P/>
<Example>
<![
CDATA[
gap> InfoLevel( InfoKan );
0
gap> ReadPackage(
"kan, "makedoc.g
" );
]]>
</Example>
<P/>
Please send bug reports, suggestions and other comments to the second author,
or use the GitHub issue tracker at
<
URL>
https://github.com/gap-packages/kan/issues/new</
URL>.
<P/>
Additional information can be found on the
<E>Computational Higher-dimensional Discrete Algebra</E> website at
<
URL>
https://github.com/cdwensley</
URL>.
</Chapter>