Yes. You are not necessarily looking for 'concessions'; you are looking for an arrangement that will suit you sufficiently well for you to abandon the idea of going to court, and the mediator is there to help you tease out what that might be. You might, for instance, get no 'concessions' at all about the issue(s) in dispute, but come away with a continuing relationship and new (and legally enforceable) payment terms - or new licences, or a new offer of co-operation in product development - that are worth far more to you.
