推理机是实施问题求解的核心执行机构，常见于专家系统。它是对知识进行解释的进程，根据知识的语义，对按一定策略找到的知识进行解释执行，并把结果记录到动态库的适当空间中去。

推理机的进程与知识库的具体内容无关，所以对知识库的修改不需要改动推理机。

An Inference Engine is a tool from artificial intelligence. The first inference engines were components of expert systems. The typical expert system consisted of a knowledge base and an inference engine. The knowledge base stored facts about the world. The inference engine applied logical rules to the knowledge base and deduced new knowledge. This process would iterate as each new fact in the knowledge base could trigger additional rules in the inference engine. Inference engines work primarily in one of two modes either special rule or facts: forward chaining and backward chaining. Forward chaining starts with the known facts and asserts new facts. Backward chaining starts with goals, and works backward to determine what facts must be asserted so that the goals can be achieved.