[plt-scheme] introspection

Hello all,

I have been trying to figure out how I can find out what the
properties of an element  are within a live environment.
e.g. I am looking at a function - what are its calling protocol is
etc.
Also useful would be a reference to where the source can be found, but
it is likely that is not stored in the running image.  I am thinking
of something like find-function in emacs.

I have searched in the manuals and the help desk, but cannot find
anything, although maybe I am looking for the wrong things.

On a related note, I know that there are no docstrings in plt scheme
such as you find in lisp and python, but in htdp and other plt related
material there seems to be a a convention that goes something like
this:

;; name-of-func : calling protocol -> return value
;; description of functionality etc.
(define name-of-func ....

Is this information actually processed in some way making it
accessible to querying from the image? I guess I can hack something
together if the find-function equivalent exists.

Thanks in advance, and really enjoying all the new (for me) features
you have added to the language.

Rohan