(subclass WMDWeaponsResearchFacility StationaryArtifact) | WMD.kif 637-637 | WMD weapons research facility is a subclass of stationary artifact |
(subclass NuclearWeaponResearchFacility WMDWeaponsResearchFacility) | WMD.kif 664-664 | Nuclear weapon research facility is a subclass of WMD weapons research facility |