Not Every Domain of a Plain Decompressor Contains the Domain of a Prefix-Free One
Résumé
C.Calude, A.Nies, L.Staiger, and F.Stephan posed the following question about the relation between plain and prefix Kolmogorov complexities (see their paper in DLT 2008 conference proceedings): does the domain of every optimal decompressor contain the domain of some optimal prefix-free decompressor? In this paper we provide a negative answer to this question.