In this note, we show that a finite collection of stable subgroups of a finitely generated group has finite height, finite width and bounded packing.

In the simulation of the NC-shape grinding process, a finite element model of the grinding machine is included. To enhance the accuracy and efficiency of the finite element computation, a posteriori error estimation and resulting adaptive mesh refinement techniques are used. In this note, a dual weighted a posteriori error estimate for a linear second order hyperbolic model problem is derived. ...

Graph structure is a flexible concept covering many different types of graph properties. Hierarchical decompositions yielding the notions of tree-width and clique-width, expressed by terms written with appropriate graph operations and associated with Monadic Second-order Logic are important tools for the construction of Fixed-Parameter Tractable algorithms and also for the extension of methods ...

Abstract We develop a method for showing that various modal logics are valid in their countably generated canonical Kripke frames must also be uncountably ones. This is applied to many systems, including the of finite width, and broader class multimodal ‘finite achronal width’ introduced here.

If a graph has no induced subgraph isomorphic to any graph in a finite family {H1, . . . ,Hp}, it is said to be (H1, . . . ,Hp)-free. The class of H-free graphs has bounded clique-width if and only if H is an induced subgraph of the 4-vertex path P4. We study the (un)boundedness of the clique-width of graph classes defined by two forbidden induced subgraphs H1 and H2. Prior to our study it was ...