可能近似正确（PAC）学习的概念在计算学习理论中具有基础性意义。
The concept of probably approximately correct (PAC) learning has been foundational in computational learning theory.
The line between madness and genius is drawn by those who fear both.
If you can't understand why someone is doing something, look at the consequences of their actions, whatever they might be, and then infer the motivations from their consequences.
Grief is love turned into an eternal missing.
I think I'm just an ordinary person who learned a bit of music.