(subclass AerobicExerciseDevice RecreationOrExerciseDevice) | Mid-level-ontology.kif 8228-8228 | Aerobic exercise device is a subclass of recreation or exercise device |
(subclass RowingMachine AerobicExerciseDevice) | Mid-level-ontology.kif 8237-8237 | Ergometer is a subclass of aerobic exercise device |