Extracting proofs from documents

Often, theorem checkers like PVS are used to check an existing proof, which is part of some document. Since there is a large difference between the notations used in the documents and the notations used in the theorem checkers, it is usually a laborious task to convert an existing proof into a format which can be checked by a machine. In the system that we propose, the author is assisted in the process of converting an existing proof into the PVS language and having it checked by PVS. 1 Introduction The now-classic ALGOL 60 report [5] recognized three different levels of language: a reference language, a publication language and several hardware representations, whereby the publication language was intended to admit variations on the reference language and was to be used for stating and communicating processes. The importance of publication language ---often referred to nowadays as "pseudo-code"--- is difficult to exaggerate since a publication language is the most effective way..

Interfacing program construction and verification

Math¿pad is a document preparation system designed and developed by the authors and oriented towards the calculational construction of programs. PVS (Prototype Verification System) is a theorem checker developed at SRI that has been extensively used for verifying software, in particular in safety-critical applications. This paper describes how these two systems have been combined into one. We discuss the potential benefits of the combination seen from the viewpoint of someone wanting to use formal methods for the construction of computer programs, and we discuss the architecture of the combined system for the benefit of anyone wanting to investigate combining the Math¿pad system with other programming tools

Defining services for mobile terminals using remote user interfaces

CE devices are increasingly extended with network support, such that the devices can be monitored or controlled remotely. At the same time, mobile phones are extended with additional network technologies, such that they can connect directly to the other devices. The use of a mobile phone as a generic remote control is investigated with a focus on the user interface (UI). Existing technologies are limited in their capabilities and user interaction models, that is, (one- way) page-based or form-based interaction. The UI fragments protocol, described in this article, has the advantages that it allows for better interaction between the user and the device (due to incremental updates, and two-way communication), and that it is an independent device (due to the use of abstract UI descriptions, in conjunction with hierarchical style sheets)