2011/01/25 by Volker Diekert, Diekert, Volker, Steffen Kopecki +1
Computer Science · #Computational Complexity (cs.CC) #FOS: Computer and information sciences #Formal Languages and Automata Theory (cs.FL) #cs.CC #cs.FL
paper · pdf · doi:10.48550/arxiv.1101.4824
arxiv created 2011/01/25 · arxiv updated 2011/01/26
The hairpin completion is an operation on formal languages which is inspired by the hairpin formation in biochemistry. Hairpin formations occur naturally within DNA-computing. It has been known that the hairpin completion of a regular language is linear context-free, but not regular, in general. However, for some time it is was open whether the regularity of the hairpin completion of a regular language is is decidable. In 2009 this decidability problem has been solved positively by providing a polynomial time algorithm. In this paper we improve the complexity bound by showing that the decision problem is actually NL-complete. This complexity bound holds for both, the one-sided and the two-sided hairpin completions.