We show that reachability and termination for lossy channel systems is exactly at level Fωω in the Fast-Growing Hierarchy of recursive functions, the first level that dominates...
We introduce PEP, the Post Embedding Problem, a variant of PCP where one compares strings with the subword relation, and PEPreg , a further variant where solutions are constrained ...
Programs and Abstract Complexity A. Beckmann University of Wales Swansea Swansea, UK Axiom systems are ubiquitous in mathematical logic, one famous and well studied example being ...
Abstract. We investigate the computational behaviour of `two-dimensional' propositional temporal logics over (N, <) (with and without the next-time operator ?) that are cap...