|  Example for Graham Clyne
   :vehicle :seatedCapacity ''30''^^xsd:integer . 
   :vehicle :standingCapacity ''10''^^xsd:integer .
   and knowledge that the total capacity is seated capacity + standing capacity, that one might infer:
   :vehicle :totalCapacity ''40''^^xsd:integer .



this-vehicle has this-capacity of type this-type
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  bus             30                    seated
  bus             10                    standing


some-vehicle has some-capacity1 of type seated
that-vehicle has some-capacity2 of type standing
that-capacity1 + that-capacity2 = some-capacity
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that-vehicle has that-capacity of type total