rebinding arrow notation

[Peter Gavin]

Section 8.3.5 of the documentation says:

   Arrow notation (see Section 8.9, “Arrow notation ”) uses whatever arr, (>>>),
   first, app, (|||) and loop functions are in scope. But unlike the other
   constructs, the types of these functions must match the Prelude types very
   closely. Details are in flux; if you want to use this, ask!

I want to do this.  Is there anything special I should know?

Pete