[DonHopkins]

Jonathan Rees's a la carte menu of the elements of "object oriented programming" is a great example of that.

http://www.paulgraham.com/reesoo.html

The Elements of Object Oriented Programming:

Encapsulation, Protection, Ad Hoc Polymorphism, Parametric Polymorphism, Everything Is An Object, All You Can Do Is Send A Message, Specification Inheritance, Implementation inheritance/Reuse, Sum-Of-Product-Of-Function Pattern.

These are the only ones of which the news has come to Harvard, and there may be many others, but they haven't been discarvered. ;)

[Apologies to Tom Lehrer.] https://www.youtube.com/watch?v=AcS3NOQnsQM