A skull can be rigid.Logical formLearned from4 sentences. A series can be constituted-of-or-filled-with rigid bodies.Logical formLearned from4 sentences. A linkage can be rigid.Logical formLearned from4 sentences. A (backbone tube) can be rigid.Logical formLearned from4 sentences. A (chain actuator) can be rigid.Logical formLearned from4 sentences. A nib can be rigid.Logical formLearned from4 sentences. A rigid inflatable boat may be launched from a slipway.Logical formLearned from4 sentences. A baton can be rigid.Logical formLearned from4 sentences. A bodyshell can be rigid.Logical formLearned from4 sentences. (Class structures) can be rigid.Logical formLearned from4 sentences. A rear suspension can be rigid.Logical formLearned from4 sentences. A harness can be rigid.Logical formLearned from4 sentences. Supporters can be rigid.Logical formLearned from4 sentences. Rotors can be rigid.Logical formLearned from4 sentences. Spars can be rigid.Logical formLearned from4 sentences.