Corrigendum to "Another approach to the equivalence of measure-many one-way quantum infinite automata and its application" [J. Comput. Syst. Sci. 78(3) (2012) 807-821]

In this paper, we present a much simpler, direct and elegant approach to the equivalence problem of measure many one-way quantum finite automata (MM1QFAs). The approach is essentially generalized from the work of Carlyle [J. Math. Anal. Appl. 7 (1963) 167-175]. Namely, we reduce the equivalence problem of MM-1QFAs to that of two (initial) vectors. As an application of the approach, we utilize it to address the equivalence problem of Enhanced one-way quantum finite automata (E-1QFAs) introduced by Nayak [Proceedings of the 40th Annual IEEE Symposium on Foundations of Computer Science, 1999, pp. 369-376]. We prove that two E-1QFAs A1 and A2 over Σ are equivalence if and only if they are n1 + n 2 2 − 1-equivalent where n1 and n2 are the numbers of states in A1 and A2, respectively.