The probabilistic guarded-command language pGCL [15] contains both demonic and probabilistic nondeterminism, which makes it suitable for reasoning about distributed random algorithms [14]. Proofs are based on weakest precondition semantics, using an underlying logic of real(rather than Boolean-) valued functions. We present a mechanization of the quantitative logic for pGCL [16] using the HOL t...

It is widely recognised that the integration of diierent (sub)-provers is a key issue in the construction of reasoning tools of practical usage. Unfortunately experience shows that eeective integration is very diicult to achieve. The Open Mechanized Reasoning Systems (OMRS) Project started in 1992 with the objective to design a formal framework for the speciication of state-of-the-art provers. ...

introduction: nowadays, imaging of the myocardial perfusion (mpi) using the single photon emission tomography (spet) in the diagnosis of coronary artery disease, especially myocardial ischemia, is of great importance. in contrast to the coronary artery angiography, mpi is non-invasive, less expensive and more physiological. unfortunately, this image is affected by the some artifacts. these arti...

We propose a practical verification framework for preemptive OS kernels. The framework models the correctness of API implementations in OS kernels as contextual refinement of their abstract specifications. It provides a specification language for defining the high-level abstract model of OS kernels, a program logic for refinement verification of concurrent kernel code with multi-level hardware ...

It is commonly accepted that tree form has an impact on the productivity of single-grip harvesters. However, it remains unclear, which elements of tree form are significant and to what degree they impact harvesting productivity. This is of particular importance in hardwood dominated stands, where hardwood trees often exhibit complex and variable stem and crown architecture that can complicate a...

This article discusses the relationship between mathematical proof and the digital computer from the viewpoint of the 'sociology of proof': that is, an understanding of what kinds of procedures and arguments count for whom, under what circumstances, as proofs. After describing briefly the first instance of litigation focusing on the nature of mathematical proof, the article describes a variety ...

Ben-Amram and Codish described SCNP [2], a subclass of the size-change termination criterion SCT [8], which permits efficient certificate checking. Termination problems in this class have a global ranking function of a certain form, which can be found using SAT solving. This note describes an automated proof reconstruction for this certificate scheme, implemented in the theorem prover Isabelle/...

It is widely believed that in principle it’s possible to reduce most of present-day mathematics to reasoning in a formal logical system. The technical difficulty of actually doing so is quite formidable. However, the arrival of the computer is changing this situation, since computers are good at helping with such tedious symbolic manipulation. The computer formalization of mathematics is now a ...

We suggest that mechanized multi-agent deontic logics might be appropriate vehicles for engineering trustworthy robots. Mechanically checked proofs in such logics can serve to establish the permissibility (or obligatoriness) of agent actions, and such proofs, when translated into English, can also explain the rationale behind those actions. We use the logical framework Athena to encode a natura...

A novel protocol has been formally analyzed using the prover Isabelle/HOL, following the inductive approach described in earlier work [10]. There is no limit on the length of a run, the nesting of messages or the number of agents involved. A single run of the protocol delivers session keys for all the agents, allowing neighbours to perform mutual authentication. The basic security theorem state...