[R6RS] Runge-Kutta

[William D Clinger]

> Would anyone like to argue for keeping it?

It would make a nice example of a complete Scheme
program, or at least a complete Scheme library,
and there's something to be said for having such
a thing at the very end of the document.  It also
would preserve our increasingly tenuous connection
to the Algol 60 report, on which our two-column
format is modelled.

I would characterize the above as a possible
rationale for keeping it, but I don't want to
argue for keeping it.  I prefer to argue about
less important things.

Will