Watson–Crick D0L systems: generative power and undecidable problems

On D0L power series

We study D0L power series. We show how elementary morphisms introduced by Ehrenfeucht and Rozenberg can be used in connection with power series, characterize the sequences of rational numbers and integers which can be appear as coe cients in D0L power series and establish various decidability results. TUCS Research Group Mathematical Structures of Computer Science

Watson-Cri k D0L Systems: the Power of One Transition

Watson-Crick D0L systems: the power of one transition

We investigate the class of functions computable by uni-transitional Watson–Crick D0L systems: only one complementarity transition is possible during each derivation. The class is characterized in terms of a certain min-operation applied to Z-rational functions. We also exhibit functions outside the class, and show that the basic decision problems are equivalent or harder than a celebrated open...

Watson-Crick D0L Systems

D0L systems constitute the simplest and most widely studied type of Lindenmayer systems. They have the remarkable property of generating their language as a (word) sequence and, consequently, are very suitable for modeling growth properties. In this paper a new type of D0L systems is introduced, where the parallelism presented in L systems is combined with the paradigm of (Watson-Crick) complem...

Undecidable Problems: a Sampler

After discussing two senses in which the notion of undecidability is used, we present a survey of undecidable decision problems arising in various branches of mathematics.