...final principal set...
(pAcme,keyid,y) 
(pCoyote,keyid,y) 
(pLadybug,keyid,y) 
(pOsh,keyid,y) 

...final policy attribute set...
pAcme.buy_flowers <- pAcme.green_thumb
pAcme.buy_rockets <- pAcme.preferred_customer
pAcme.green_thumb <- pLadybug
pAcme.preferred_customer <- pCoyote
pOsh.buy_rockets <- pOsh.preferred_customer
pOsh.preferred_customer <- pCoyote
pOsh.preferred_customer <- pLadybug

===good============ Acme.buy_rockets <- Coyote
YAP query succeed
pAcme.buy_rockets <- pAcme.preferred_customer
pAcme.preferred_customer <- pCoyote

===bad============ Acme.buy_rockets <- Ladybug
YAP query failed

===good============ Osh.buy_rockets <- Ladybug
YAP query succeed
pOsh.buy_rockets <- pOsh.preferred_customer
pOsh.preferred_customer <- pLadybug