Efficiently Depth-First Minimal Pattern Mining

Abstract. Condensed representations have been studied extensively for 15 years. In particular, the maximal patterns of the equivalence classes have received much attention with very general proposals. In contrast, the minimal patterns remained in the shadows in particular because of their difficult extraction. In this paper, we present a generic framework for minimal patterns mining by introducing the concept of minimizable set system. This framework addresses various languages such as itemsets or strings, and at the same time, different metrics such as frequency. For instance, the free and the essential patterns are naturally handled by our approach, just as the minimal strings. Then, for any minimizable set system, we introduce a fast minimality check that is easy to incorporate in a depth-first search algorithm for mining the minimal patterns. We demonstrate that it is polynomial-delay and polynomial-space. Experi-ments on traditional benchmarks complete our study