#1 |--------------------|
#2 |---------------| |---------|
#3 |------------| |---|
#4 |----| |------| |--|
#5 |---------------------|
Each of these channels have overlapping event. Some sessions happen strictly before the other. Sometimes, one logs on before the other one logs of. Etc. The more channels we have the more complex behavior. That is all the paper is saying.Sorry about that.