Barriers can be artificial.Logical formLearned from802 sentences. A surface can be artificial.Logical formLearned from573 sentences. An environment can be artificial.Logical formLearned from413 sentences. Means can be artificial.Logical formLearned from383 sentences. Systems can be artificial.Logical formLearned from363 sentences. Skin can be artificial.Logical formLearned from332 sentences. An artificial heart can be self-contained.Logical formLearned from293 sentences. Boundaries can be artificial.Logical formLearned from285 sentences. A deadline can be artificial.Logical formLearned from285 sentences. A timetable can be artificial.Logical formLearned from282 sentences. Ones can be artificial.Logical formLearned from257 sentences. A distinction can be artificial.Logical formLearned from250 sentences. Methods can be artificial.Logical formLearned from249 sentences. A feeding can be artificial.Logical formLearned from247 sentences. An amplification can be artificial.Logical formLearned from247 sentences.