Abstract: A method for building a knowledge base containing entailment relations, including providing at least one input pattern (p) with N pattern slots (N>1), the input pattern (p) expressing a specific semantic relation between N entities that fill the N pattern slots of the input pattern (p) as slot fillers, providing at least one cluster (c) of articles, the articles of the cluster (c) relating to a common main topic; processing the articles with respect to the input pattern (p) and identifying the identities which match the semantic type of the N pattern slots; if the at least one input pattern matches a portion of an article (a) of the at least one cluster (c): storing the N slot fillers (s1, s2, . . . , sN), which match the slots of the pattern (p), and a cluster identifier Ic of the cluster (c) into a first table S, wherein the N-tuple (s1, s2, . . .