Computation Theory and Logic

Egon Börger ist Professor für Informatik an der Universität Pisa (Italien) und Alexander-von-Humboldt-Forschungspreisträger.

Minimal pairs for polynomial time reducibilities.- Primitive recursive word-functions of one variable.- Existential fixed-point logic.- Unsolvable decision problems for PROLOG programs.- You have not understood a sentence, unless you can prove it.- On the minimality of K, F, and D or: Why löten is non-trivial.- A 5-color-extension-theorem.- Closure relations, Buchberger's algorithm, and polynomials in infinitely many variables.- The benefit of microworlds in learning computer programming.- Skolem normal forms concerning the least fixpoint.- Spectral representation of recursively enumerable and coenumerable predicates.- Aggregating inductive expertise on partial recursive functions.- Domino threads and complexity.- Modelling of cooperative processes.- A setting for generalized computability.- First-order spectra with one variable.- On the early history of register machines.- Randomness, provability, and the separation of Monte Carlo Time and space.- Representation independent query and update operations on propositional definite Horn formulas.- Direct construction of mutually orthogonal latin squares.- Negative results about the length problem.- Some results on the complexity of powers.- The Turing complexity of AF C*-algebras with lattice-ordered KO.- Remarks on SASL and the verification of functional programming languages.- Numerical stability of simple geometric algorithms in the plane.- Communication with concurrent systems via I/0-procedures.- A class of exp-time machines which can be simulated by polytape machines.- ???-Automata realizing preferences.- Ein einfaches Verfahren zur Normalisierung unendlicher Herleitungen.- Grammars for terms and automata.- Relative konsistenz.- Segment translation systems.- First steps towards a theory of complexity over moregeneral data structures.- On the power of single-valued nondeterministic polynomial time computations.- A concatenation game and the dot-depth hierarchy.- Do there exist languages with an arbitrarily small amount of context-sensitivity?.- The complexity of symmetric boolean functions.