is.seqelist checks wether the argument is an event
sequence object while is.seqe checks wether the argument is a
single element of an event sequence object.
There is a print method that can be applied to such event sequence object.is.seqe(s)
is.seqelist(s)str.seqelist, str.seqe,as.character.seqelist and as.character.seqe to convert sequences from an event sequence object into character strings