tmql as xtm output

Hi,
I´m currently working on a project that allows an application to send
topicmap queries to a remote topicmap engine. As query language I use tolog
in tm4j as it is already available. I´m looking for a way (maybe the best
one ;-)) to serialize the results of the query to a "streamable" format to
be able to transfer it over the wire. I thought of using xtm as it is a
standard interchange format for topic maps.
I already discussed this issue with Kal, but I think that this is also
interesting for people working on tmql. In tolog there are predefined
predicates which allows to execute some predefined operations like
retrieving all base names for a specific topic. In this case, the resultset
only contains basenames but no topics. I think it is not possible to create
a basename in xtm without creating a corresponding topic. My thought was to
create a dummy topic for each basename but this will produce a lot of
overhead and will decrease the performance.
What do you think? I know that tmql should be able to create xtm output. For
that reason this question could be interesting for you to discuss.
Regards,
Stefan