Wang, Ming-Wei On the irregularity of the duplication closure. (English) Zbl 0983.68111 Bull. Eur. Assoc. Theor. Comput. Sci. EATCS 70, 162-163 (2000). Summary: We solve a problem proposed in “On the regularity of the duplication closure” by J. Dassow, V. Mitrana and Gh. Păun [ibid. 69, 133-136 (1999; Zbl 0941.68605)]. Cited in 11 Documents MSC: 68Q45 Formal languages and automata Citations:Zbl 0941.68605 PDFBibTeX XMLCite \textit{M.-W. Wang}, Bull. Eur. Assoc. Theor. Comput. Sci. EATCS 70, 162--163 (2000; Zbl 0983.68111)