A concept can be rigid.Logical formLearned from23 sentences. A testing can be rigid.Logical formLearned from23 sentences. A principle can be rigid.Logical formLearned from23 sentences. (Cell walls) can be rigid.Logical formLearned from23 sentences. A skeleton can be rigid.Logical formLearned from23 sentences. A syntax can be rigid.Logical formLearned from23 sentences. A (seniority system) can be rigid.Logical formLearned from23 sentences. Limbs can be rigid.Logical formLearned from22 sentences. A self-control can be rigid.Logical formLearned from22 sentences. A cap can be rigid.Logical formLearned from22 sentences. A part can be rigid.Logical formLearned from22 sentences. A metal can be rigid.Logical formLearned from22 sentences. A pin can be rigid.Logical formLearned from22 sentences. A box can be rigid.Logical formLearned from22 sentences. A lens can be rigid.Logical formLearned from22 sentences.