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| 必須制約 (A constraint that requires every instance of an object type's population to play that role. With a disjunctive mandatory role constraint, each member of the object type's population must play at least one of the roles indicated) | |||
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| 必須制約 (A constraint that requires every instance of an object type's population to play that role. With a disjunctive mandatory role constraint, each member of the object type's population must play at least one of the roles indicated) | |||
