Theory Is Forever Essays Dedicated to Arto Salomaa on the Occasion of His 70th Birthday

This commemorative book celebrates the 70th birthday of Arto Kustaa Salomaa, one of the most influential researchers in theoretical computer science.
The 24 invited papers by leading researchers in the area address a broad variety of topics in theoretical computer science and impressively reflect the breadth and the depth of Arto Salomaa's scientific work.

Duality for Three: Ternary Symmetry in Process Spaces.- Mathematical Proofs at a Crossroad?.- Rational Relations as Rational Series.- Networks of Standard Watson-Crick D0L Systems with Incomplete Information Communication.- On the Size of Components of Probabilistic Cooperating Distributed Grammar Systems.- Remarks on Sublanguages Consisting of Primitive Words of Slender Regular and Context-Free Languages.- A Semiring-Semimodule Generalization of ?-Context-Free Languages.- Integer Weighted Finite Automata, Matrices, and Formal Power Series over Laurent Polynomials.- Two Models for Gene Assembly in Ciliates.- On Self-Dual Bases of the Extensions of the Binary Field.- On NFA Reductions.- Some Results on Directable Automata.- Rectangles and Squares Recognized by Two-Dimensional Automata.- Substitution on Trajectories.- Recombination Systems.- Algebraic Aspects of Parikh Matrices.- On Distributed Computing on Elliptic Curves.- On the Formal Modelling of Trust in Reputation-Based Systems.- Issues with Applying Cryptography in Wireless Systems.- On a Tomographic Equivalence Between (0,1)-Matrices.- P Systems with Tables of Rules.- Some Properties of Multistage Interconnection Networks.- Structural Equivalence of Regularly Extended E0L Grammars: An Automata Theoretic Proof.- Complexity of Evolving Interactive Systems.