"A book is a fragile creature, it suffers the wear of time, it fears rodents, the elements and clumsy hands. So the librarian protects the books not only against mankind but also against nature and devotes his life to this war with the forces of oblivion."

诗歌不是一种奢侈品，而是一种必需品。

真相既简单又复杂。

For systems, the analogue of a face-lift is to add to the control graph an edge that creates a cycle, not just an additional node.