Python-based HEX implementation for a fragment of the HEX language and a subset of features.
Python Shell Prolog
Switch branches/tags
Nothing to show
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.

Build Status codebeat badge Anaconda-Server Badge

HEXLite Python-based solver for a fragment of HEX

This is a solver for a fragment of the HEX language and for Python-based plugins which is based on Python interfaces of Clingo and WASP and does not contain any C++ code itself.

The intention is to provide a lightweight system for an easy start with HEX.

The vision is that HEXLite can use existing Python plugins and runs based on the Clingo or WASP python interface, without realizing the full power of HEX.

The system is currently under development and only works for certain programs:

  • External atoms with only constant inputs are evaluated during grounding in Gringo
  • External atoms with predicate input(s) and no constant outputs are evaluated during solving in a clasp Propagator
  • External atoms with predicate input(s) and constant outputs that have a domain predicate can also be evaluated
  • Liberal Safety is not implemented
  • Properties of external atoms are not used
  • If it has a finite grounding, it will terminate, otherwise, it will not - as usual with Gringo
  • FLP Check is implemented explicitly and does not work with strong negation and weak constraints
  • FLP Check can be deactivated

A manuscript about the system is under preparation.

In case of bugs please report an issue here:

  • License: GPL (3.0)

  • Author: Peter Schüller

  • Available at PyPi:

  • Installation with Conda:

    The easiest way to install hexlite is Conda.

    First you need to install the clingo dependency:

    $ conda install -c potassco clingo

    Then you install hexlite:

    $ conda install -c peterschueller hexlite

    (If you wonder why we do not automatically install clingo as a dependency: certain conda restrictions prevent that clingo is automatically installed unless the potassco channel is manually added by the user.)

    Then you test hexlite:

    $ hexlite -h

  • Installation with pip:

    This will download, build, and locally install Python-enabled clingo modules.

    • If you do not have it: install python-pip: for example under Ubuntu via

      $ sudo apt-get install python-pip

    • Install hexlite:

      $ pip install hexlite --user

    • Setup Python to use the "Userinstall" environment that allows you to install Python programs without overwriting system packages:

      Add the following to your .profile or .bashrc file:

      export PYTHONUSERBASE=/.local/ export PATH=$PATH:/.local/bin

    • Run hexlite the first time. This will help to download and build pyclingo unless it is already usable via import clingo:

      $ hexlite

      The first run of hexlite might ask you to enter the sudo password to install several packages. (You can do this manually. Simply abort and later run hexlite again.)

    • Ubuntu 16.04 is tested

    • Debian 8.6 (jessie) is tested

    • Ubuntu 14.04 can not work without manual installation of cmake 3.1 or higher (for buildling clingo)

Developer Readme

  • For developing hexlite without uploading to anaconda repository:

    • Install clingo with conda, but but do not install hexlite with conda.

    $ conda install -c potassco clingo

    • checkout hexlite with git

    $ git clone

    • install hexlite in develop mode into your user-defined Python space:

    $ python3 develop --user

    • If you want to remove this development installation:

    $ python3 develop --uninstall --user $ rm ~/.local/bin/hexlite

    (Installed scripts are not automatically uninstalled.)

  • Build and upload new conda package.

    • Update version in meta.yaml.

    • Run

    $ conda build .

    • Run anaconda upload command at the end of the output.