I'm looking for free online texts about recursion.
What I'm looking for formal definitions* of "all" (most of) the different types of recursion and from different points of views like Category theory too .
For example I did read a text where the author talks about the "successor algebra" $(\Bbb N,S)$ (he calls it in this way) and how there exist an unique homomorphism $f: \Bbb N \rightarrow X$ between the "successor algebra" and another structure $(X,e)$ such that $f \circ S = e \circ f$ and that $f$ can be easily identified with a function defined recursively on the natural numbers by $S$ and $e$
so what I need is:
A general overview of everything that concerns the recursion in a synthetic way but NOT FROM THE POINT OF VIEW OF COMPUTER.
note: I'm also interested if there is some general discussion of the process of recursion as a kind function $R$ that map functions, for example $f$ and $S$ to another function $F=R(f,S)$ that is "defined recursively"
Related Question: Differend kind of recursion