[Haskell-beginners] (->) instance for ArrowApply and laziness

[aditya siram]

Hi all,
Could someone help me understand how the (->) instance for ArrowApply
works? It looks like this:
> instance ArrowLoop (->) where
>         loop f b = let (c,d) = f (b,d) in c

This models recursion for arrows and I need help understanding how it
does that. I have a strong feeling it has to do with the magic value
'd'. I've read the Patterson tutorial but I still don't grok it.

Thanks!
-deech