In this paper, we show how a system for automated deduction can be given computational reeection, i.e. can aaect its own computation mechanism, by using the very same machinery implementing logical deduction. This feature, that we call computational reeection via mechanized logical deduction, provides both theoretical and practical advantages. First, the theorem prover can inspect, extend and m...

Otter-lambda is a theorem-prover based on an untyped logic with lambda calculus, called Lambda Logic. Otter-lambda is built on Otter, so it uses resolution proof search, supplemented by demodulation and paramodulation for equality reasoning, but it also uses a new algorithm, lambda unification, for instantiating variables for functions or predicates. The basic idea of a typed interpretation of ...

We study a general framework for query rewriting in the presence of an arbitrary first-order logic ontology over a database signature. The framework supports deciding the existence of a safe-range first-order equivalent reformulation of a query in terms of the database signature, and if so, it provides an effective approach to construct the reformulation based on interpolation using standard th...

A general technique is presented that allows property based feature analysis of systems consisting of an arbitrary number of components. Each component may have an arbitrary set of safe features. The components are defined in a guarded command form and the technique combines model checking and abstraction. Features must fulfill certain criteria in order to be safe, the criteria express constrai...

We revisit the approach deened in 2] for the formal veriication of cryptographic protocols so as to allow for some mechanization in the veriication process. In the original approach veriication uses theorem proving. Here we show that for a wide range of practical situations and properties it is possible to perform the veriication on a nite and safe abstract model.

We present a tool for reachability analysis of continuous systems based on affine arithmetic and Runge-Kutta methods. The distinctive feature of our tool is its verification in the interactive theorem prover Isabelle/HOL: the algorithm is guaranteed to compute safe overapproximations, taking into account all round-off and discretization errors.

In his dissertation [3], Olin Shivers introduces a concept of control flow graphs for functional languages, provides an algorithm to statically derive a safe approximation of the control flow graph and proves this algorithm correct. In this research project [1], Shivers’ algorithms and proofs are formalized using the HOLCF extension of the logic HOL in the theorem prover Isabelle.

In this paper I describe a implementation procedure for generating controllers to guarantee safety constraints for controllable discrete-time linear systems. The first two sections are a summary of the work of [6]. The contribution of this paper is the discussion of the limitations of this method and future research directions. We omit any discussion of complexity and focus instead on functiona...

The UniForM-Workbench is an open tool integration environment providing type safe communication, a toolkit for graphical user interfaces, version management and connguration management. It is speciically geared towards formal methods and based on the encoding of formal methods into the theorem prover Isabelle. The UniForM-Workbench thus tackles both the technical and the semantical problems ari...

Public-Key-Infrastrukturen sind von zentraler Bedeutung für eine sichere elektronische Kommunikation in offenen Netzen. PublicKey-Infrastrukturen bergen aber für die auf ihnen basierenden Anwendungen auch Risiken, weil die Verfahren der PKIs zu Grunde liegenden Public-Key-Kryptografie nicht beweisbar sicher sind. Zur Lösung der möglichen Probleme – Verlust der Verfügbarkeit von PKIAnwendungen, ...