

![0_image_0.png](0_image_0.png)

<process:hasPrecondition> <expr:KIF-Condition rdf:ID="ExistTGV"> <expr:expressionBody rdf: datatype="http://www.w3.org/2001/XMLSchema\#string"> 
 (ExistTGV ?From ?To) 
 </expr:expressionBody> </expr:KIF-Condition> </process:hasPrecondition> 
The proposed architecture arranges of a set of sub-ontologies. Each sub-ontology includes all the concepts of certain type of Web services. For example, a sub-ontologyi which represents the services of booking of any type of transport, another one which includes the Web services of booking of hotels, etc. We thought of this decomposition to improve the time answer to the requests. 

## 5.1. **Role Of Ontologies In Interaction**

As autonomous problem solvers, agents need to develop model of their environment that allows them to reason on how their actions affect their environment and how those changes lead them to achieve their goals [28]. Ontologies provide the conceptual framework that allows agents to construct such models: ontologies describe the properties of entities that agents encounter, and relations between them. Thus a common vocabulary in the form of ontologies is at the heart of intelligent communication among agents. 

## 5.2. **Preliminary Definitions**

In this section, we introduce some definitions necessary for the understanding of the proposed architecture functioning as well as that of the proposed composition model. 