RE: viewpoints and multiple inheritance.
Here is an interesting example of multiple inheritance based upon the state
at an instance.
In the US a seaplane is a:
1. airplane when flying that requires lighting for aircraft
2. uncontrolled boat when landing that require lighting for an uncontrolled
boat
3. controlled boat when taxiing that requires lighting for a controlled boat
Douglas D. Mann
Battelle Memorial Institute
5109 Leesburg Pike Suite 819
Falls Church, Virginia 22041-3208
MannD@battelle.org
Phone +1 703 575 2114
Fax +1 703 671 9180