We present a simple-to-state, abstract computational problem, whose solution implies the 1consistency of various systems of predicative Analysis and offers a way of extracting witnesses from classical proofs. In order to state the problem, we formulate the concept of transfinite update procedure, which extends Avigad’s notion of update procedure to the transfinite and can be seen as an axiomati...

This paper studies mathematically some special kinds of transfinite trace semantics and investigates program slicing w.r.t. these semantics. Several general facts about slicing, which hold for a wide class of programming languages and their transfinite semantics, are proven. The principal part of the work is done on control flow graphs keeping the treatment abstracted from any concrete programm...

We propose a fast stiffness matrix calculation technique for nonlinear finite element method (FEM). Nonlinear stiffness matrices are constructed usingGreen-Lagrange strains, which are derived from infinitesimal strains by adding the nonlinear terms discarded from small deformations. We implemented a linear and a nonlinear finite element method with the same material properties to examine the di...

Step-indexed logical relations are an extremely useful technique for building operational-semantics-based models and program logics realistic, richly-typed programming languages. They have proven to be indispensable modeling features like higher-order state , which many languages support but were difficult accommodate using traditional denotational models. However, the conventional wisdom is th...

A comparison between two diierent command governors strategies (CG) is described. A CG is a nonlinear device which is added to a primal compensated system. The CG action, based on the current state, set-point and prescribed constraints, is nalized to select, at any time, a command sequence under which the constraints are possibly fulllled with acceptable tracking performance. The two CG's diier...