[erlang-questions] set of sets module

[Frans Schneider]

Dear list,

I am looking for some more material on the sofs module besides the 
standard Erlang documentation. Google doesn't come up with much 
interesting stuff. Does anybody know of some teaching material?
Also, I am wondering for what type of application the sofs module was 
developed for in the first place. Are their any public available 
applications using the sofs functionality?

TIA

Frans