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
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
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