The development of formal systems has revolutionized our understanding of mathematics.
他不满他所拥有的，也不会满足他想要的。
Make it simple. Make it memorable. Make it inviting to look at. Make it fun to read.
数学的研究是所有智力和精神进步不可或缺的基础。
I have come to believe that a great teacher is a great artist and that there are as few as there are any other great artists. Teaching might even be the greatest of the arts since the medium is the human mind and spirit.