[qznc]

Defining a function is already a mechanism of abstraction. You take a snippet of code and give it a name. Usually you generalize by adding parameters. Maybe you can even make it generic (C++ templates, Java Generics, Haskell typeclasses, etc). Removing the abstraction of a function means to inline the code. You could do that manually (copy&paste).

I wrote more on this here: http://beza1e1.tuxen.de/precise_abstractions.html

Abstracting is not everything there is to programming, but modern code consists nearly completely of abstractions.