fplll-tools software package provides Tools to compute LLL-reduction of Euclidian lattices, you can install in your Debian 9 (Stretch) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install fplll-tools
fplll-tools is installed in your system.
Make ensure the fplll-tools package were installed using the commands given below,
$ sudo dpkg-query -l | grep fplll-tools *
You will get with fplll-tools package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | Mathematics |
| Package | fplll-tools |
| Version | 5.0.3-1 |
| Description | Tools to compute LLL-reduction of Euclidian lattices |
| Sub Section | Math |