A heart can be hollow.Logical formLearned from21 sentences. A thunk can be hollow.Logical formLearned from21 sentences. Claims can be hollow.Logical formLearned from21 sentences. A tower can be hollow.Logical formLearned from21 sentences. Steel can be hollow.Logical formLearned from21 sentences. Fills can be hollow.Logical formLearned from21 sentences. A statue can be hollow.Logical formLearned from21 sentences. Construction can be hollow.Logical formLearned from20 sentences. A cube can be hollow.Logical formLearned from20 sentences. Echoes can be hollow.Logical formLearned from20 sentences. A class can be hollow.Logical formLearned from20 sentences. An out can be hollow.Logical formLearned from20 sentences. A (taker chamber) can be hollow.Logical formLearned from20 sentences. A silence can be hollow.Logical formLearned from20 sentences. Figures can be hollow.Logical formLearned from20 sentences.