String representations have the following form:
  time-(e1,e2,...)-elapsedtime-(e3,...)...
  where time is the time elapsed from start to the first set of simultaneous events (e1,e2,...) and elapsedtime the time between two consecutive sets of simultaneous events. Time is only displayed when events are time stamped.
  Use str (str.seqelist) to get a single string for a whole list, and as.charcater (as.character.seqelist) to get a vector of strings.
  str.eseq and as.character.eseq have mainly an internal purpose (invoked by print methods for example).