(=> (instance ?C ElectricalConductor) (exists (?S) (and (subclass ?S ConductorSubstance) (material ?S ?C)))) |
engineering.kif 826-831 | |
(subclass ConductorSubstance Substance) | engineering.kif 1281-1281 | |
(subclass Electrolyte ConductorSubstance) | Cars.kif 2495-2495 |