A nod can be hollow.Logical formLearned from13 sentences. A beat can be hollow.Logical formLearned from13 sentences. An exception can be hollow.Logical formLearned from13 sentences. A comfort can be hollow.Logical formLearned from13 sentences. Claims may ring hollow.Logical formLearned from13 sentences. A soul can be hollow.Logical formLearned from13 sentences. Symbols can be hollow.Logical formLearned from13 sentences. A head can be hollow.Logical formLearned from13 sentences. Promises may prove hollow.Logical formLearned from13 sentences. A rhetoric can be hollow.Logical formLearned from13 sentences. An effort can be hollow.Logical formLearned from13 sentences. A pledge may ring hollow.Logical formLearned from13 sentences. Cages can be hollow.Logical formLearned from13 sentences. A trunk can be hollow.Logical formLearned from13 sentences. Lives can be hollow.Logical formLearned from13 sentences.