Is it correct saying that the Zero, Successor and Projection functions can be seen as combinators?



Is it correct to state that basic primitive recursive functions are in fact combinators?
Yes, if I'm right in assuming you mean to ask whether these can be construed without free variables in the lambda calculus. (If my assumption is wrong, I apologize; your question is rather terse.) You can see [here](http://en.wikipedia.org/wiki/Church_encoding), for instance, how the "Church numerals" (Zero among them, of course) can be introduced, along with Successor and various other primitive recursive functions.


