Volume 37 • Number 3 • 2014   • On Some Decompositions of r-Disjunctive Languages Di Zhang, Yuqi Guo and K. P. Shum Abstract. Some kinds of decompositions of r-disjunctive languages on an arbitrary alphabet will be investigated. We will show that an f-disjunctive (t-disjunctive) language can be divided into two parts and either one part of them is an f-disjunctive (t-disjunctive) language or both parts are r-disjunctive but not f-disjunctive (t-disjunctive) languages. Finally, a relevant result of H. J. Shyr and S. S. Yu concerning the disjunctive languages will be improved. 2010 Mathematics Subject Classification: 20M35 Full text: PDF