Local type info for compilation

[JONL at MIT-MC (Jon L White)]

(+ <frob>)  is preferable to (+ <frob> 0) for announcing that <frob>
will be of type FIXNUM (similarly for +$ and FLONUM), and most likely
that will do whereever you wanted a local type specification.
   If there is going to be some other key word, I would suggest something
without the word "force" in it, since the action here is not a type
coercion to one type or other, but rather merely the "telling" of information
to some processor (compiler, data checker, interpreter).