What is the function from which all other functions can be derived?

Question

I seem to remember reading about a function that could be used to make all other functions. Does anyone know what it is? And how could such a function be used?

I can't remember where I read it and my google-fu is not strong enough.

Answer 1

Maybe you are thinking about combinator calculus, and there especially the iota combinator mentioned at the bottom of this section.

Answer 2

You may mean: http://en.wikipedia.org/wiki/SKI_combinator_calculus

Or: http://en.wikipedia.org/wiki/Turing_machine

Or: eval