Exercise 2.82: Show how to generalize
apply-generic to handle coercion in the general case of multiple
arguments.  One strategy is to attempt to coerce all the arguments to the type
of the first argument, then to the type of the second argument, and so on.
Give an example of a situation where this strategy (and likewise the
two-argument version given above) is not sufficiently general.  (Hint: Consider
the case where there are some suitable mixed-type operations present in the
table that will not be tried.)