Database Reference
In-Depth Information
Pasture
Arable
Meadow
FIGURE 9.2
Venn diagram of farmland types. Spots represent members of the three sets
Arable, Pasture, and Meadow.
ings that have
responsibility
for some Property
Valuation
ings that have responsibility
for some Land Registration
Land Management
Agency
FIGURE 9.3
Venn diagram of organizations' responsibilities.
separate Rabbit statements as shown in the Land Management Agency example that
follows. Whenever you encounter the keyword “or” in OWL, you should understand it
to mean “either one or other or both,” and the keyword “and” in OWL refers to when
the thing is a member of
both
sets. For example, the Land Management Agency has
responsibility for Land Registration and Property Valuation.
Land Management Agency has
responsibility for Land Registration.
Land Management Agency has
responsibility for Property Valuation.
Individual: LandManagementAgency
Facts: hasResponsibilityFor
some LandRegistration and
hasResponsibilityFor some
PropertyValuation
It sometimes flows better to use the word
that
when linking two classes, so both
the Rabbit and Manchester Syntaxes also allow “that” as a keyword instead of “and”
to aid the reader, although again the use of “that” within Rabbit is more restrictive.
