Discovering an Algorithm Actually Learning Restricted Single Occurrence Regular Expression with Interleaving.

A recent paper proposed an algorithm iSOIRE, which combines single-occurrence automaton (SOA) and maximum independent set (MIS) to learn a subclass single-occurrence regular expressions with interleaving (SOIREs) and claims the learnt expression is SOIRE, which has unrestricted usage for interleaving. However, in reality, the learnt expression still has many restrictions for using interleaving, even does for Kleene-star or interation, i.e, the learnt expression is not an SOIRE, we prove that by examples. In this paper, for the algorithm iSOIRE, we first give the basic notions, then provide analyses about incorrectness, finally present the correct result learnt by iSOIRE. Our theoretical analyses demonstrate that the result derived by iSOIRE belongs to a subclass of SOIREs.