计算机是第一个元媒体，因此它在表示和表达方面具有前所未有的自由度。
The computer is the first metamedium, and as such it has degrees of freedom for representation and expression never before encountered.
The art of doing mathematics consists in finding that special case which contains all the germs of generality.
There is no method but to be very intelligent.
"Books are the maps that guide us through life."