As will be clear from our discussion of “has part,” it is possible to ask in regard to any relation defined in an ontology whether there is another relation that goes, as it were, in the other direction—generally referred to as the inverse relation. The inverse of a relation R is defined as the relation that obtains between each pair of relata of R when taken in reverse order.
However, for most of the relations that we have defined, it is not possible to define an inverse relation in this direct fashion. This makes it necessary to define what have been called reciprocal relations.
To see the problem consider the assertion human testis continuant_part_of human,which passes the all-some test. When we attempt to formulate the assertion in the opposite direction, however, the resulthuman has_continuant_part human testisfails by the all-some test, because not all humans have testes. Has_continuant_part is not the inverse but rather what we call the reciprocal of continuant_part_of. Something similar holds for the adjacent_to relation, for while we have for adult humansuterine artery adjacent_to urinary bladderwe do not haveurinary bladder adjacent_to uterine arterysince male humans do not have a uterine artery.
上下文:Inversion and Reciprocity
As will be clear from our discussion of “has part,” it is possible to ask in regard to any relation defined in an ontology whether there is another relation that goes, as it were, in the other direction—generally referred to as the inverse relation. The inverse of a relation R is defined as the relation that obtains between each pair of relata of R when taken in reverse order.
However, for most of the relations that we have defined, it is not possible to define an inverse relation in this direct fashion. This makes it necessary to define what have been called reciprocal relations. To see the problem consider the assertion human testis continuant_part_of human,which passes the all-some test. When we attempt to formulate the assertion in the opposite direction, however, the resulthuman has_continuant_part human testisfails by the all-some test, because not all humans have testes. Has_continuant_part is not the inverse but rather what we call the reciprocal of continuant_part_of. Something similar holds for the adjacent_to relation, for while we have for adult humansuterine artery adjacent_to urinary bladderwe do not haveurinary bladder adjacent_to uterine arterysince male humans do not have a uterine artery.
位置:7_218
推荐翻译:逆 和 相反