MultiMaster Replication

I've been reading up on multimaster replication and had a few questions.

1. After the multimaster replication setup there needs to be a master definition site. if the communication breaks between 2 sites will we have to change the master definition site.
2. the tables the i'm trying to replicate have sequences that i need to transform to sequences on the other side.

oracle seems to say its possbile but i cant find an example.

If anyone on the list has had experience with multimaster. if they could drop me an email and we could chat a little bit offline that would be really great.  

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