Theory Is Forever

This Festschrift celebrates the 70th birthday of Arto Kustaa Salomaa (born in Turku, Finland on June 6, 1934), one of the most in?uential researchers in theoretical computer science. Most ofhis researchconcernstheory he is one of the founding fathers of formal language and automata theory, but he has also made important contributions to cryptography and natural computing. His approach to research in theoretical computer science is exemplary and inspirational for his students, collaborators, andthereadersofhispapersandbooks. Forhim,theroleoftheory(incomputer science) is to discover general rules of information processing that hold within computer science and in the world around us. One should not waste time on research concerning passing artifacts (or fashionable topics of the moment) in computer science theory should be permanently predictive, insightful, and inspiring. That s why we chose the title Theory is Forever . The main source of his in?uence on theoretical computer science is his publi- tions. Arto is a born writer his papers and books are always most elegant. He has a unique gift for identifying the real essence of a research problem, and then presenting it in an incisive and eloquent way. He can write about a very involved formal topic and yet avoid a (much too common) overformalization. Many of his writings are genuine jewels and belong to the classics of theoreticalcomputer science. Theyhaveinspiredgenerationsofstudentsandresearchers. Indeed,even computers as well as computer science have learned a lot from Arto s publi- tions this is nicely illustrated by DADARA on the cover of this volume.

Includes supplementary material: sn.pub/extras

Autorentext
Hermann Maurer studierte Mathematik und Physik in Österreich, Informatik in Kanada. Er war einige Jahre in der Industrie tätig, aber ist nun seit mehr als 30 Jahren Universitätsprofessor für Informatik an Universitäten in Kanada, USA, Deutschland, Brasilien, Australien, Neuseeland und vor allem an der Technischen Universität Graz in Österreich. Er ist mit zahlreichen wissenschaftlichen Büchern und über 500 wissenschaftlichen Publikationen in seinem Bereich der Informatik aktiv tätig, ist aber auch seit vielen Jahren schriftstellerisch aktiv, oft unter einem Pseudonym.

Inhalt
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.