The PAC learning framework provides a formal way to analyze the efficiency and effectiveness of learning algorithms.

I have a vivid memory of what happened， and it was not what I expected. I expected to be applauded for my cleverness and arithmetic skills. "Jeff， you're so smart. You had to have made some tricky estimates， figure out the number of minutes in a year and do some division." That's not what happened. Instead， my grandmother burst into tears. I sat in the backseat and did not know what to do. While my grandmother sat crying， my grandfather， who had been driving in silence， pulled over onto the shoulder of the highway. He got out of the car and came around and opened my door and waited for me to follow. Was I in trouble？ My grandfather was a highly intelligent， quiet man. He had never said a harsh word to me， and maybe this was to be the first time？ Or maybe he would ask that I get back in the car and apologize to my grandmother. I had no experience in this realm with my grandparents and no way to gauge what the consequences might be. We stopped beside the trailer. My grandfather looked at me， and after a bit of silence， he gently and calmly said， "Jeff， one day you'll understand that it's harder to be kind than clever."

小说是讲述真相的谎言。

事物背后必定隐藏着某些极为深奥的东西。

"每个人都有自己的故事，而作家的任务就是把这些故事编织成永恒的文字。"