(subclass ElectricalPowerGeneration PowerGeneration) | Economy.kif 2069-2069 | ElectricalPowerGeneration est une sous-classe de PowerGeneration |
(subclass HydroElectricPowerGeneration ElectricalPowerGeneration) | Economy.kif 2077-2077 | HydroElectricPowerGeneration est une sous-classe de ElectricalPowerGeneration |