The Liskov Substitution Principle is a fundamental concept in object-oriented programming, ensuring that derived classes can be used in place of their base classes without altering the correctness of the program.

What is love except another name for the use of positive reinforcement? Or vice versa.

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.

Most people are afraid of change, but if you look at it like it's something that can always count on, then it can be a comfort．It doesn't have many things that you can count on．

给学生一些事情去做，而不是一些东西去学；而这些事情的性质需要思考；学习会自然而然地发生。