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# The GAP 4 package 'NormalizInterface'

## Package description

Normaliz is a software for computations with rational cones and affine
monoids. It pursues two main computational goals: finding the Hilbert
basis, a minimal generating system of the monoid of lattice points of a
cone; and counting elements degree-wise in a generating function, the
Hilbert series.
As a recent extension, Normaliz can handle unbounded polyhedra. The
Hilbert basis computation can be considered as solving a linear
diophantine system of inhomogeneous equations, inequalities and
congruences.

This package allows creating libnormaliz cone objects from within GAP,
and gives access to it in the GAP environment. In this way GAP can be
used as interactive interface to libnormaliz.

For more information on Normaliz visit
<https://www.normaliz.uni-osnabrueck.de/>
and especially have a look at the manual.


## Installation

NormalizInterface supports GAP 4.9 or later, and Normaliz 3.5.4 or later.
However, we recommend using the most recent versions -- at the time this
is written, that means GAP 4.11.1 and Normaliz 3.9.1.

Assuming you have a suitable version installed, you still need to
compile Normaliz. There is a complicating factor, however: Normaliz
must be compiled against the exact same version of the GMP library
as GAP. The easiest way to do that is to run the script we provide
to you for just that.  This requires the presence of several further
system software packages, which you could for example install via
your system's package manager. At least the following are required,
in addition to a C++11 compiler:

 * curl OR wget for downloading the source code

Once you have installed these, you can build Normaliz by using the
`prerequisites.sh` script provided by us. If NormalizInterface is
installed inside the `pkg` directory of your GAP installation, you
can simply invoke it from inside the NormalizInterface directory as
follows:

    ./prerequisites.sh

Otherwise, you have to tell the script where your GAP directory is,
by passing it as an argumnt:

    ./prerequisites.sh GAPDIR

Not specifying GAPDIR is equivalent to passing `../..` as GAPDIR. If
more than one argument is specified, then any arguments beyond the
first are passed on to the Normaliz `configure` script.

Once the script completed successfully, you can build NormalizInterface
like this:

    ./configure --with-gaproot=GAPDIR
    make

The ` --with-gaproot=GAPDIR` parameter is actually optional, and if omitted,
the package will search for GAP in `../..`.


## Documentation and tests

Generate the documentation:

    gap makedoc.g

run automatic tests:

    gap tst/testall.g


## Bug reports and feature requests

Please submit bug reports and feature requests via our GitHub issue tracker:

  <https://github.com/gap-packages/NormalizInterface/issues>


## License

NormalizInterface is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

For details see the file LICENSE.
