(Border controls) can be rigid.Logical formLearned from22 sentences. A focus can be rigid.Logical formLearned from22 sentences. (Plastic containers) can be rigid.Logical formLearned from22 sentences. Positions can be rigid.Logical formLearned from22 sentences. Molecules can be rigid.Logical formLearned from21 sentences. A hierarchical structure can be rigid.Logical formLearned from21 sentences. An uniformity can be rigid.Logical formLearned from21 sentences. A class can be rigid.Logical formLearned from21 sentences. A person may go rigid.Logical formLearned from21 sentences. A spine can be rigid.Logical formLearned from21 sentences. Formats can be rigid.Logical formLearned from21 sentences. A (party discipline) can be rigid.Logical formLearned from21 sentences. An intolerance can be rigid.Logical formLearned from21 sentences. Boundaries can be rigid.Logical formLearned from21 sentences. A father can be rigid.Logical formLearned from21 sentences.