Definition 1: An adlet is defined as
adlet = (doc, profile, target, non-target, ad-strategy, prop) where
doc uniquely identifies the document to be advertised,
profile is a set of conceptual relations from a concept space characterizing this document,
target is a set of conceptual relations characterizing documents to be recruited,
non-target is a set of conceptual relations characterizing documents to be avoided,
ad-strategy is the advertising strategy, and
prop are other properties.
Definition 2: Two adlets ad1 and ad2 can be partially ordered as follows,
ad1 < ad2, if and only if the following holds:
a) doc1 = doc2,
b) profile1 = profile2,
c) target1 is contained in target2,
d) non-target1 contains non-target2,
e) ad-strategy1 = ad-strategy2, and
f) prop1 = prop2.
Definition 3: The negotiation protocol
is a sequence e-proc= ((d11,d12), (d21,d22), ..,
(dn1,dn2)), where each (di1,di2) is an exchanged pair of documents
and the final pair (dn1,dn2) is a pair of goal documents.
Definition 4: A negotiation protocol is supportable if the adlets can
induce a sequence of information exchanges e-seq such that e-seq contains
e-proc as a subsequence and the final pair (dn1,dn2) of e-seq is
a pair of goal documents.