Using admissibility for a computable model theory for uncountable structures

A well-known problem in intuitionistic logic is the existence of valid but not derivable rules. This problem seems to be related with some constructive features of intuitionism (disjunction and existence property) but appear also in modal logics. We study here a particular case of this phenomenon, admissible rules in propositional calculus. G.E.Mints in [Mi 72] give sufficients conditions for a...

Deduction modulo is a framework in which theories are integrated into proof systems such as natural deduction or sequent calculus by presenting them using rewriting rules. When only terms are rewritten, cut admissibility in those systems is equivalent to the confluence of the rewriting system, as shown by Dowek, RTA 2003, LNCS 2706. This is no longer true when considering rewriting rules involv...

For any finite and consistent first-order theory, we can find a presentation as a rewriting system that enjoys cut admissibility. Since proofs are rarely built without context, it is essential to develop methods that are adapted to search for proofs in theories. For instance, SMT provers provide efficient tools. Nevertheless, they are restricted to some particular theories, such as linear arith...

We analyse the notion of iterated admissibility, i.e., avoidance of weakly dominated strategies, as a solution concept for extensive games of infinite horizon. This concept is known to provide a valuable criterion for selecting among multiple equilibria and to yield sharp predictions in finite games. However, generalisations to the infinite are inherently problematic, due to unbounded dominance...

Sufficient conditions for the finite and infinite-time admissibility of an observation operator are given. It is shown that the estimates of Weiss are close to being sufficient. If the semigroup is surjective, then the estimate is sufficient.

We give an overview of results, presented in the form of a poster at CSL03/KGC, about a general study of the notions of rule derivability and admissibility in Hilbert-style proof systems. The basis of our investigation consists in the concept of “abstract Hilbert system”, a framework for Hilbert-style proof systems in which it is abstracted from the syntax of formulas and the operational conten...

In this work we present a new approach to the study of the stability of admissible shock wave solutions for systems of conservation laws that change type. The systems we treat have quadratic ux functions. We employ the fundamental wave manifold W as a global framework to characterize shock waves that comply with the viscosity admissibility criterion. Points of W parametrize dynamical systems as...

unwillingness of the competent state to prosecute and investigate an international crime within the jurisdiction of the international criminal court is one of the aspects of admissibility of a case in the court. unwillingness is originally a subjective concept and is capable for a vast interpretation therefore may endanger the basic goal of complementarity principle i.e. respecting states sover...