Negotiation Among Web Services Using Lotos/cadp

It is now well-admitted that formal methods are helpful for many issues raised in the web service area. in a previous work, we advocated the use of process algebra to describe, compose and reson on web services at an abstract level. In this paper, we extend this initial proposal, which only dealt with behavioural aspects, to cope wiche the question of representing data aspects as well. In this context, we show how the expressive process algebra LOTOS (and its toolbox CADP) can be used to tackle this issue. We illustrate the usefulness of our proposal on an important application in e-business: negotiation among web services. The connection between concrete thanks to sysrematic guidelines enabling one to map LOTOS and the executable language BPEL in both directions