Semantics of Preconditions and Effects

Hi All,

I am trying to understand the semantics of preconditions and effects . 
In one of the papers

Narayanan, S. and McIlraith, S., "Simulation, Verification and Automated 
Composition of Web Services",

I found that preconditions for any service can also be modelled as 
knowledge based apart from physical preconditions.For e.g: agent 
Knows(bookName) for a service like LocateBook. I am interested in 
knowing whether agent can have knowledge based effects as well for e.g: 
agent Knows(ISBN), especially for information providing services.

Any thoughts appreciated.

Cheers,

Monika
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Monika Solanki
Software Technology Research Laboratory(STRL)
De Montfort University
Hawthorn building, H00.18
The Gateway
Leicester LE1 9BH, UK

phone: +44 (0)116 250 6170 intern: 6170
email: monika@dmu.ac.uk
web: http://www.cse.dmu.ac.uk/~monika
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