Object models for computer aided design

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66 T􁪽􋵥e ebjec􁪽􋵨 header 􁪽􋵳s epl􁪽􋵴t i􁪽􋴺:c 􁪽􋴚􁪽􋵥e areas. Ir. t::e 􁪽􋴚􁪽􋵲rst area 􁪽􋴚􁪽􋵥e kev f􁪽􋵥elds are def􁪽􋴚􁪽􋵥ed. :he def􁪽􋴚􁪽􋴚􁪽􋵴t􁪽􋵣cr. fer (Kev fiel􁪽􋴡 !􁪽􋵳st> is ir. section 4.6, but for t􁪽􋵥e rre􁪽􋵥e􁪽􋵴t the reader 􁪽􋵡ay thi􁪽􋵫k of this list as beir.g si􁪽􋵩ilar to t::e 􁪽􋴚􁪽􋵥eld de:;tll:odel=rrocel oel?tscherna; { s cb err.a is sterec in list of a Pascal recorc defi􁪽􋵩ition. The secor.d part of the object header contains tte nor.-key fields. The field l􁪽􋵳st definition for this part of the object header 25 􁪽􋵴tat 􁪽􋵣cr an attritute. The exarr􁪽􋵬le illustrates a Fartial rrooel definitio􁪽􋴮. c ep t s ch en.e :This is 2 sarrple sc!;erra fer an acaderric depcrtrrent} o e c t s c r.e ra } ecjt:.:;;e (cie􁪽􋵴t,prof); (dept and prof are the objects} 2􁪽􋵴tr:v;e (faculty/prefref,chair􁪽􋵡an/educ/􁪽􋵥egree, putlist,pub); {attributes fer cept and prof} 􁪽􋵣cefir.ition of#dept object header} cep:=etject cclleges: {file for cept c􁪽􋵪jects} prctectior. {begin protection definition} e n t e r c c j , "v e r y s e c r e t ": {'very􁪽􋵴tScre:' i s leek s t r i nc } re􁪽􋵯oveetj, 'verysecret': e cc e s s cc j I' secret': {different lock for access} upc a t e c c j , t v e r y s e c r e t '