The ‘literate’ programming model is extended to include a concept of mechanical transformation. A prototype tool, FLP (Formal Literate Programming tool), has been developed which uses this extended ‘literate’ programming model in both a formal program proof setting, and within a formal (refinement) program development setting. In both settings, FLP provides history, access to tools, and an easy...

These lectures are designed to provide a general introduction to the Einstein-Vlasov system and to the global Cauchy problem for these equations. To start with some general facts are collected and a local existence theorem for the Cauchy problem stated. Next the case of spherically symmetric asymptotically flat solutions is examined in detail. The approach taken, using maximal-isotropic coordin...

Known proposals for key establishment schemes based on combinatorial group theory are often formulated in a rather informal manner. Typically, issues like the choice of a session identifier and parallel protocol executions are not addressed, and no security proof in an established model is provided. Successful attacks against proposed parameter sets for braid groups further decreased the attrac...

We present a formal tool for verification of multivariate nonlinear inequalities. Our verification method is based on interval arithmetic with Taylor approximations. Our tool is implemented in the HOL Light proof assistant and it is capable to verify multivariate nonlinear polynomial and non-polynomial inequalities on rectangular domains. One of the main features of our work is an efficient imp...

We present an original theorem in auction theory: it specifies general conditions under which the sum of the payments of all bidders is necessarily not identically zero, and more generally not constant. Moreover, it explicitly supplies a construction for a finite minimal set of possible bids on which such a sum is not constant. In particular, this theorem applies to the important case of a seco...

Graphical Interval Logic (GIL) is a visual temporal logic in which formulas resemble the informal timing diagrams familiar to system designers and software engineers. It provides an intuitive and natural visual notation in which to express speciications for concurrent systems and retains the beneets of a formal notation. A visual editor permits GIL speciications to be easily constructed, and to...

Background Informal payments for health care, which are common in many countries, can have negative effects on health care access, equity and health status as they lead people to forgo or delay seeking care, or to sell assets to pay for care. Many countries are putting reforms in place with the aim of reducing informal payments. In order to be successful, such policies should be informed by the...

Process discovery techniques return process models that are either formal (precisely describing the possible behaviors) or informal (merely a “picture” not allowing for any form of formal reasoning). Formal models are able to classify traces (i.e., sequences of events) as fitting or non-fitting. Most process mining approaches described in the literature produce such models. This is in stark con...

We give a detailed, informal proof of the Church-Rosser property for the untyped λ-calculus and show its representation in LF. The proof is due to Tait and Martin-Löf and is based on the notion of parallel reduction. The representation employs higher-order abstract syntax and the judgments-as-types principle and takes advantage of term reconstruction as it is provided in the Elf implementation ...