著名数学家、中国科学、中国科学院院士杨乐教授在北京航空航天大学做学术报告回答学生提的关于数学研究的问题时 ,举了这样一个例子 ,大意是 :一个数学理论的证明过程可能会有二十几步 ,仔细研究一下就会发现 ,这二十几步可能要分成三个部分 ,第一部分分若干步 ,证明了一个问 Academician Yang Le, a renowned mathematician, academician of the Chinese Academy of Sciences and a member of the Chinese Academy of Sciences, gave an academic report to answer questions raised by students on mathematics research at Beijing University of Aeronautics and Astronautics. He gave an example to the effect that the proof process of a mathematical theory may have In 20 or more steps, if you look closely, you will find that these 20 steps may be divided into three parts. The first part is divided into several steps and proves a question.