Grundzüge der Logik und Noëtik im Geiste des hl. Thomas von Aquin, von Dr Sebastian Huber

Gribomont E. Grundzüge der Logik und Noëtik im Geiste des hl. Thomas von Aquin, von Dr Sebastian Huber. In: Revue néo-scolastique. 15ᵉ année, n°59, 1908. p. 423

Grundzüge der Logik und Noëtik im Geiste des hl. Thomas von Aquin, von Dr Sebastian Huber

Gribomont E. Grundzüge der Logik und Noëtik im Geiste des hl. Thomas von Aquin, von Dr Sebastian Huber. In: Revue néo-scolastique. 15ᵉ année, n°59, 1908. p. 423

Atomicity Refinement and Trace Reduction Theorems

. Assertional methods tend to be useable for abstract, coarse-grained versions of concurrent algorithms, but quickly become intractable for more realistic, finer-grained implementations. Various trace-reduction methods have been proposed to transfer properties of coarse-grained versions to finer-grained versions. We show that a more direct approach, involving the explicit construction of an (inductive) invariant for the finer-grained version, is theoretically more powerful, and also more appropriate for computer-aided verification. 1 Introduction Recents improvements in methods and tools for testing the validity of propositional and predicate logic formulas have revived the interest in assertional methods for concurrent system verification. Indeed, at least as far as safety properties are concerned, Hoare's logic and Dijkstra's predicate transformer calculus reduce the correctness problem for programs to the validity problem for logical formulas. However, as soon as loops occur in pro..

Preprocessing for Invariant Validation

Hoare's logic and Dijkstra's predicate transformer calculus have proved adequate for reducing the correctness problem for programs to the validity problem for logical formulas. However, the size of the logical formulas to be validated grows faster than the size of the program, and, even in the propositional case, the validation problem is NPcomplete and becomes practically intractable for large programs. We introduce a strategy for dealing with this problem. The principle is to write the formulas in the form (h 1 \Delta \Delta \Delta hn ) ) c, and to use efficiently computable criteria to select a small subset I ae f1; : : : ; ng such that c remains a logical consequence of H I = fh i : i 2 Ig. These criteria are motivated and the efficiency of the method is investigated

Decidability of Invariant Validation for Parameterized Systems

The control part of many concurrent and distributed programs reduces to a set Pi = {p1, ..., pn} of symmetric processes containing mainly assignments and tests on Boolean variables. However, the assignments, the guards and the program invariants can be Pi-quantified, so the corresponding verification conditions also involve Pi-quantifications. We propos

Reactive variables for system specification and design

. A reactive system takes action when some event (induced by the environment) occurs. It is not easy to transform informal requirements about such a system into formal specifications, nor to refine these specifications into a correct design. The notion of reactive variable, introduced in this paper, can make the specification-design process easier. 1 Introduction Numerous languages have been proposed to represent formal specifications of programs and more general systems. (See for instance [4] for an overview.) Specification languages are often declarative, i.e. logic-based, to reach a sufficiently abstract level of description. However, the declarative style is not so well-adapted to the specification of reactive systems, since logical formulas have to specify not only what modifications are induced by some event occurrence, but also that many things are not affected by this occurrence; besides, it is not only necessary to specify that the causes induce the event, but also that the ..