Parks can be empty.Logical formLearned from20 sentences. Cavities can be empty.Logical formLearned from20 sentences. A (center tank) can be empty.Logical formLearned from20 sentences. A prefix can be empty.Logical formLearned from20 sentences. Villages can be empty.Logical formLearned from20 sentences. A port can be empty.Logical formLearned from20 sentences. (Drink cans) can be empty.Logical formLearned from20 sentences. A bridge can be empty.Logical formLearned from20 sentences. Pockets can be empty.Logical formLearned from20 sentences. Grandstands can be empty.Logical formLearned from20 sentences. A (coke bottle) can be empty.Logical formLearned from20 sentences. Pledges can be empty.Logical formLearned from20 sentences. A pavement can be empty.Logical formLearned from20 sentences. Thousands of seats can be empty.Logical formLearned from20 sentences. A pail can be empty.Logical formLearned from19 sentences.