You could be interested by https://testfiledownload.com (a GPLv3+ software for Linux, hopefully some potential successor to CLIPS). it enables you to represent conceptual graphs. Contact me by email to basile@starynkevitch.net (home, near Paris in France) or basile.starynkevitch@cea.fr (work, at https://www-list.cea.fr/ ...). However, RefPerSys is alpha-quality software.... Thank so much Basile STARYNKEVITCH