“…Though their influence (more than considerable in fields as decision theory [14,17,26,29] or machine learning [19]) has spread separately, in the last few decades both notions have started to appear together in many developments on these and other fields (see for instance [4,6,13,15,30,31,38]), which comes to show its high relevance as a topic of research inside soft computing [20] and logics [36].…”