“…Nowadays, a variety of computational systems, from credit card transactions, through wearable gadgets, to video surveillance, create enormous amounts of data, mostly in sequential fashion. Since this abundant -however raw -data do not provide interesting behavior patterns, data mining techniques, especially inductive learning, have been applied to extract useful knowledge from this type of data [13,10,21,6]. Extracting patterns from data streams and their usage in real-time is an effervescent research topic that has been tackled during the last decades [14,27,4,15,28].…”