A rear end can be rigid.Logical formLearned from4 sentences. A (line inclusion) can be rigid.Logical formLearned from4 sentences. A fern can be rigid.Logical formLearned from4 sentences. A (frictionless surface) can be rigid.Logical formLearned from4 sentences. Analytic functions can be rigid.Logical formLearned from4 sentences. (Quota systems) can be rigid.Logical formLearned from4 sentences. A schooling can be rigid.Logical formLearned from4 sentences. A society can be rigid.Logical formLearned from4 sentences. A meter can be rigid.Logical formLearned from4 sentences. A consensus can be rigid.Logical formLearned from4 sentences. An elimination can be rigid.Logical formLearned from4 sentences. A parenting can be rigid.Logical formLearned from4 sentences. Facings can be rigid.Logical formLearned from4 sentences. Footings can be rigid.Logical formLearned from4 sentences. Some points may be fixed on a rigid body.Logical formLearned from4 sentences.