  Service Oriented Architectures (SOAs) are component-based architectures,
characterized by reusability, modularization and composition, usually offered
by HTTP (web services) and often equipped with a Quality of Services (QoS)
measure. In order to guarantee the fairness property to each client requesting
a service, we propose a fair version of the (Soft) Concurrent Constraint
language to deal with the negotiation phases of the Service Level Agreement
(SLA) protocol.
