** If you have a program that makes several changes in the same area<BR>
of the buffer, you can use the macro combine-after-change-calls 
around that Lisp code to make it faster when after-change hooks
are in use.
<P>
The macro arranges to call the after-change functions just once for a
series of several changes--if that seems safe.
<P>
Don't alter the variables after-change-functions and
after-change-function within the body of a combine-after-change-calls
form.
<P>