
MyProgram3 relegates all of the real work
to a class named RangeProduct.

MyProgram4 illustrates the use of an inner
class -- in this case MyRangeProduct -- which
extends RangeProduct, and replaces its
toString() method, so that the numerical
output is listed first (which makes it
easier to do sorting on the results).

Note that MyRangeProduct is only meant to
be used inside class MyProgram4.

