推理机

代码说明：

  实现简单推理机功能，主要包括子条件、不确定性、与或及结论的录入，论据的添加，进行正向推理及逆向推理(The function of simple inference engine is realized, which mainly includes the input of sub-conditions, uncertainties, and/or conclusions, the addition of arguments, forward inference and reverse inference.)