Translating E/R-diagrams into consistent database specifications

Semi formal methods, for example those which are used in the database community, are useful for communication between developers and clients. But they are not useful for formal verification.To overcome this problem it is possible to translate E/R-diagrams into first order algebraic specifications. The aim of our task was to prove the consistency of such translate specifications. To realize the proof we use the KIV (Karlsruhe Interactive Verifier) approach for the development of correct large software systems, i.e. we prove the consistency indirect by proving the correctness of an implementation. For this purpose we automatically translate E/R-diagrams not only in an algebraic specification, but in a modular system containing structured specifications and implementations. For a concrete E/R-diagram we can prove the correctness with the KIV system. Because the translation is uniform a generalized handmade proof for arbitrary but fixed E/R-diagrams is possible, and presented in this paper. This paper also includes an exemplary translation of an E/R-diagram with 5 entities and 6 relations. The generated modular system contains 33 specifications with more than 300 specified operations and more than 500 axioms. Furthermore the implementation contains more than 2200 lines of code

Integrating processes in temporal logic

In this paper we propose a technique to integrate process models in classical structures for quantified temporal (modal) logic. The idea is that in a temporal logic processes are ordinary syntactical objects with a specific semantical representation. So we want to achieve a `temporal logics of processes\u27 to adequately describe aspects of systems dealing with data structures, reactive and time-critical behavior, environmental influences, and their interaction in a single frame. Thus the structural information of processes can be captured and exploited to guide proofs. As an instance of this scheme we present a quantified, metric, linear temporal logic containing processes and conjunctions of processes explicitly. Like a predicate a process can be regarded as a special kind of atomic formula with its own intension, a family of sets collecting the observable behavior as `runs\u27. A run is comparable with a Hoare-traces or a timed observational sequence it is a sequence of sequences of values taken from a set of objects. Each single value can be regarded as a snapshot of an observable feature at a moment in time, e.g. a value transmitted through a channel. Such a set has to respects the structure of the underlying temporal logic, but not one to one, we do not require that for a path in the time structure there is exactly one possible run. Since each run has a certain length, the view of a run is in particular associated with a time interval. The difference between moments and intervals of time is expressed by several kinds of modal operators each of them with restrictions in the shape of annotated equations and predicates to determined the relevant time slices. We describe syntax and semantic of this logic especially with a focus on the process part. Finally we sketch a calculus and give some examples

A general method for the synthesis of C-glycosides of nojirimycin

Methyl 2,3,4,6-tetra-O-acetyl-N-(benzyloxycarbonyl)nojirimycin (3) can be readily transformed into the corresponding azaglycal 6 or fluoride 7, which are versatile glycosyl/piperidinosyl donors. Reaction of 7 with allyltrimethylsilane, propinyltrimethylsilane, trimethylsilyl cyanide, and trimethylsilyl enol ether as carbon nucleophiles, afforded, in the presence of BF3 . OEt2 as catalyst, the corresponding C-glycosides 8-10 and 12-14 in good yields. The anomeric configurations of the C-glycosides are ascertained with the help of ROESY-NMR data