[credentials]
EPub.discount <- EOrg.preferred ^ EPub.student
EOrg.preferred <- ACM.member
EOrg.preferred <- IEEE.member
ACM.member <- Alice
ACM.member <- Cindy
ACM.member <- Brian
EPub.student <- EPub.university.stuId
EPub.university <- ABU.accredited
ABU.accredited <- StateU
StateU.stuId <- Alice
StateU.stuId <- Cindy

[sensitive]
IEEE.member
StateU.stuId

[traceable]
spdiscount
preferred
student
university

[searches]
EPub.discount 
EOrg.preferred ^ EPub.student
EOrg.preferred 
IEEE.member
ACM.member 
EPub.student 
EPub.university.stuId
EPub.university 
ABU.accredited
StateU
StateU.stuId 
Alice
Brian