tailieunhanh - Research Issues in Systems Analysis and Design, Databases and Software Development phần 9

có nghĩa là, â € x: PossibleAllMaleState [x là thực tế - ‰ ¡âƒy: Sở (x là của y & â € z: Người (công trình z cho y ⊃ z là nam)). Hạn chế deontic bây giờ có thể được chụp bởi các hạn chế văn bản sau đây vào loại thực tế â € œRuleAdoption là forbiddenâ €: | Modality of Business Rules 221 that is Vx PossibleAllMaleState x is actual Ey Department x is ofy Vz Person z works for y o z is male . The deontic constraint may now be captured by the following textual constraint on the fact type RuleAdoption is forbidden RuleAdoption is forbidden if RuleAdoption is by a Department and is of a Rule that obligates the actualization of a PossibleAllMaleState that is of the same Department that is Vx RuleAdoption Vy Department Vz Rule Vw PossibleAllMaleState x is by y x is of z z obligates the actualization of w w is of y o x is forbidden . The formalization of the deontic constraint works because the relevant instance of PossibleAllMaleState exists regardless of whether or not the relevant Figure complex case involving embedded mention of propositions PossibleAllMaleState is actualiff PossibleAllMaleState is ofa Department and each Person who works for that Department is male 1 RuleAdoption is forbidden if RuleAdoption is by a Department and is of a Rule that obligates the actualization ofa PossibleAllMaleState that is of the same Department Copyright 2007 IGI Global. Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited. 222 Halpin department actually is all male. The obligates the actualization of and is actual predicates embed a lot of semantics which is left implicit. While the connection between these predicates is left informal the derivation rule for PossibelAllMaleState is actual provides enough semantics to enable human readers to understand the intent. Alternatively we could adopt one of two extremes a treat the rule overall as an uninterpreted sentence or informal comment for which humans are to provide the semantics or b translate the semantic formulation directly into higher order logic which permits logical formulations which connote propositions to be predicated over. The complexity and implementation overhead of Option 2 would seem to be very substantial. We